I'm not really familar with MoO yet but why has MoO2 been patched to 1.40 already? It's kinda uncommon for GOG to apply fan patches for their releases.
Latest official version is 1.31.
And anyway: thanks for bringing this to the site. :)

Yeh, the menu says it's version 1.40b23

Well, I asked why and not if they applied that patch. ;)

Oh, I'm sorry. I must have missed that little "why" in there :P

Isn't the 1.40 patch a Dos only patch?

Yes it is and GOG officially supports only the DOS version of the game. You can find more about the unofficial patch by visiting it's home page.
Here's the changelog:
May 22, 2006 - version 1.40b23
*******************************
- Corrected a problem with the /nohousing switch which could cause
it to only apply to players that had the switch on their command
line. All players should now receive the settings from the host.
- Corrected another problem where the /nohousing switch could override
the settings stored in a saved game when loaded. This included the
stored settings for some other switches. Now the settings should be
loaded from the save game file and command line switches should not
have and effect on a loaded game.
- Fixed a problem with black hole generators that caused them not to
destroy ships when ship initiative was enabled.
- Fixed a problem in a display redraw routing that sometimes resulted
in memory outside the VESA display memory window to be overwritten.
This bug could cause random crashes and lockups.
- Fixed another problem with a display redraw routing that sometimes
resulted in memory outside of the video frame buffers to be overwritten.
This could cause parts of the save game to become corrupted, random
crashes, and other strange behavior.
- Fixed a problem that could cause the game to crash when a player was
using tractor beams.
Jan 24, 2006 - version 1.40b22
*******************************
- Corrected the problem that cause the "Please load VESA.COM" error
even when you have a VESA VBE enabled video card. This eliminates
the need for vesawrap except when you go to run the game installer.
- Corrected bug that occurs with ships equipped with the Cloak or
Phasing Cloak technology. These ships will no longer be visible to
long range scans on the Galaxy Map.
- Corrected bug that occurs during combat with ships equipped with
the Phasing Cloak technology. These ships should now always revert
to regular cloaking after 10 rounds as the manual states.
- Added a /noscan switch. This switch will disable the scan button in
combat so that detailed scans of ships will no longer be possible.
Only quick scans will be possible by mousing over the ships.
- Added a /nohousing switch. The housing option will no longer be
available from the build list so housing production will not be
possible. Also, this switch adds +150% bonus to population growth.
The bonus will be added into the growth formula exactly the same
way that the bonus from universal antidote is.
- Added a cluster galaxy for single player games only which has more
stars in the same area as a large galaxy.
- Added a /nonebula switch. When use the map is generated without any
nebulas.
- Changed the /minstart swtich (again) so that rich/ultra rich
large/huge normal G planets are not generated.
July 30, 2005 - version 1.40b21
*******************************
- Fixed bug where combat ships are deleted when you land troops.
- Fixed bug where fighter bays is still researchable in post warp.
July 16, 2005 - version 1.40b20
*******************************
- Fixed a bug that caused colony ships and outpost ships to be undeleted after
they have been used to create a colony or outpost.
- Fixed the /noorion switch so that it removes Orion and the Guardian rather
than moving the system off the map. A regular system is left in its place.
- Changed the /nobh switch so that the type of star the black hole is converted
to is random rather than always red.
- Added /noreport - The report button on the diplomacy screen will be disabled
preventing you from seeing what technology your opponent has. Also, Technology
demands and trades are greyed out.
- Added /droids - All players start out with the ability to build androids (all 3 types).
- Changed post warp tech age - players will receive all tech up to 250RPs except
fighter bays. Creative races will also no longer receive fighter bays in post warp.
Feb 19, 2005 - version 1.40b19
*****************************
- Corrected minor bug in autoexec2.nt script creation when kali is not detected.
- Added new Post Warp technology age.
- Fixed repeat build bug.
- Improved dosx for SP2 detection. Better support for non-US versions of windows.
- Added 32K of code space to the game file.
Oct 27, 2004 - version 1.40b18
******************************
- New patcher engine
- Improved autoexec2.nt in XP
- Patcher should now detect the path to Kali correctly when generating autoexec2.nt
- Improved dosx version checking. It will only patch SP2 dosx.
- Detects orion2 version. Now it will only patch the DOS v1.31 english version
- Modem Comm Info button is now greyed out.
- Fix for some video cards misreporting "missing vesa.com"
- Now patcher creates the orion2v140.pif file automatically in game directory.
- Patcher now creates a .lnk file on the desktop rather than a .pif file
Sept 16, 2004 - version 1.40b17
*******************************
- Fix for stealth technology. Now ships equiped with the
technology work as stated in the manual.
- Quick fix for windows XP SP2 dosx.exe. The new dosx in SP2
crashes during orion2 LAN games. This seems due to a change
in the way dosx handles DPMI. The patch attempts to
create a patched copy of dosx.exe (dosx_sp1.exe) which is
equivalent to the dosx from SP1.
May 21, 2004 - version 1.40b16
******************************
- Added rkernel fix for Windows XP. Corrects problem with
sending packets during LAN game play in windows XP.
- Added desktop icon creation. This will make an desktop
icon for launching LAN games over Kali.
Feb 28, 2004 - version 1.40b15 (earlier versions not logged so all
****************************** previous updates are listed here)
- Disabled Modem Comm Info button (room for patch). Null modem
Comm Info Button still works.
- Disabled TEN button (room for patch).
- Fix for credit cheat bug. You can no longer produce a ship and
trade goods on the same planet in a single turn .
- Fix for ship leader & no ship crash bug. The game will no
longer crash when you view ship leaders and you have no ships.
- Fix for arti bug. Arti planet bonus will no longer vanish in
LAN games.
- Fix for esc from race picks screen. Pressing ESC on the race
picks screen used to go back 2 screens. It now goes back 1
screen.
- Removed last race button from multiplayer game screens to avoid
crashing.
- Home systems now have at least 1 colonizable planet + homeworld.
- New command line switches - various command line switches
have been added to improve the map generator.
/nowh No wormholes are generated on new maps
/nobh No black holes are generated on new maps
/noorion Orion is hidden on new maps ( cannot be reached )
/minstart The unoccupied planet closest to the sun in all
home systems will be at least 2 production per
worker to a normal G race.
/hugestart The unoccupied planet closest to the sun in all
home systems will be huge and its gravity will
match that of the homeworld.
/richstart The unoccupied planet closest to the sun in all
home systems will be rich and its gravity will
match that of the homeworld (this switch is
ignored if /goodstart is used).
/goodstart The unoccupied planet closest to the sun in all
home systems will be Ultra Rich and its gravity
will match that of the homeworld.
/nosplint No splinter worlds unless there is a monster
guarding it.
/planets=# Sets the minimum number of planets in all home
systems to #. This value includes the home
world. Valid values are 2-5 (default is 2).
If you try a value outside of the valid range
it will use the default.
/picks=# Sets the starting race picks points to #.
Valid values are 10-14 (default is 10). If you
try a value outside of the valid range it will
use the default. Note: some screens in the game
only show the first 11 race picks (it is
possible to pick more than 11).

Hi, I am in the process of downloading this game right now. As I was looking for information on this version/patch, I ended up at the website where the 1.40 patch comes from. It appears that last year (2010) there was another patch (1.40b24) released, which doesn't add or change anything, but rather fixes some problem(s) with the program that applies the patch. This program can now be run directly in DosBOX. I don't know if it can be used with this version of the game, however, it's something for GOG to consider, since I'm assuming they are the ones who patched the game. (Note, Gamer's Gate is also selling the patched version of the game, I haven't checked with anyone else that provides electronic game distribution. - Correction, Gamer's Gate says it's installing 1.40, but when you run the game, it says it's version 1.31, so you have the option to get the 1.40b24 patch, if you wish, and run it under DosBOX.)

Oh, and lest you think I'm plugging Gamer's Gate, let me say this: You may find some games cheaper over there at times, but they use their own download program which runs the installer right after download, then when it's done installing, it changes the name of the installer (or setup) program, and also changes some bytes in it (somehow), so changing the name back doesn't allow you to run it (you have to run their downloader again to install it again). This makes GOG the hassle-free choice, regardless of price (and what's a couple dollars when you're talking about ease of use?).

The 1.4b24 patcher source code is also available, in case you want to make your own patches. For more information, check out http://lordbrazen.blogspot.com/