I have Windows 7 and can't seem to run DKED (which I was pleasantly surprised to see was included in the game's directory!). Is there some way to run it in DOSBox? It really is one of the greatest editing tools ever made for a game, one I always enjoyed with Darklands 'back in the day' ... and would love to be able to use it again, now.

I would move it to where you have the Darklands game files and run it through DOSBox.

One way is to have a setup like this in the dosbox config file (dosboxDarklands.conf):
C:
CD DARKLAND
DARKLAND.EXE
#DKED.EXE

The # makes a line a comment, causing it to be ignored. In that example it shows the editor commented out. If you wanted to run the editor you'd just switch the # to the game's executable instead, then switch it back when you want to run the game.

Alternatively you can use a different shortcut with "-conf dosboxDarklands.conf" changed to run a different config file which has DKED.EXE set to run instead of DARKLAND.EXE. No need to keep editing the config file, just run the other shortcut.

Finally there is a Dosbox frontend called D-Fend Reloaded that supports additional files for a program, changing config in a menu, and other things to make it easier. If you were trying to set up the game from scratch anyway I'd definitely recommend it, but with GOG already having done so it is probably more work than it'll save.

-Edit- If you installed it to the default directory in win7, the config file you want to mess with is in:
"\Users\{profile name}\AppData\Local\VirtualStore\Program Files (x86)\GOG.com\Darklands\"
"{profile name}" in there is your win7 user/profile name.
If dosboxDarklands.conf isn't already there, copy it there. The saves are in:
"\Users\{profile name}\AppData\Local\VirtualStore\Program Files (x86)\GOG.com\Darklands\DARKLAND\SAVES"

The files in those directories will override the ones in the normal "Program Files (x86)" the game installed to. Windows doesn't like files in Program Files being altered directly, and does this to get around it. It can be avoided entirely by installed the game to somewhere not protected like the root directory, or your own program directory like "C:\moreprograms\" instead.

Forget all the fuss!

Here how it goes:

Open 2 windows, one next to the other!
One showing the folder where the editor is (no need to copy it anywhere!)
The other showing the folder where dosbox is.

Now you just grab the icon of the editor in one window, and carefully pull it across to the other window,
and pull it ONTO the icon of dosbox!

VOILAAAA

program started and now you can edit all the characters you want! :D