I am not asking for their presence here. I would love to, but I doubt it will happen. (not just GOG)
I know that Sid bought their licenses, at least for those with his name on them, a few years back. Among them personal favourites of mine like Silent Service (I have easily played this game for over 500 hours) , F-15 Strike Eagle, etc etc. Any idea of if (Firaxis?) they are working on any remakes/sequels of those old games?
Games like those mentioned, or Midwinter, Gunship, M1 Tank Platoon (must have spent 400+ hours on it), Knights of the Sky, Red Storm Rising, Stunt Car RAcer, The Ancient Art of War in the Skies...
Classics all of them, but any chance of seeing remakes/sequels of them?

I don't know about the flight sims...that's a genre that isn't nearly as big when those games first came out. It's a pretty niche segment of gaming these days, so I don't know that Firaxis would be pouring resources in to re-imagining some of those.

I think Sid like you said only has the rights to games with his name on them. The rest of the titles you mentioned are probably with Atari and as they are here on GOG it's possible they will turn up at some point.

Well the progression leads that way. It was Microprose then Spectrum HoloByte then Hasbro Interactive who then sold most of everything to Infogrammes who became atari
in the house that jack built
Depending on the way the licences fell, there's a fair chance that they are with Atari and I know that a Microprose Collection would be a welcome addition to the catalogue

Heh, looks like people aren't reading the OP.
Anyway, no, I don't think we'll see remakes or sequels to any of these games. I mean, you should never say never, but I think the only way this would happen would be if we got a King's Bounty-like situation where another company simply buys the rights.
(as for Stunt Car Racer, a remake/sequel was on the cards a few years ago, but it never happened)

As a 2K company I don't know if you really want Firaxis reviving old IPs right now. 2K are not being too sympathetic to poor old XCOM after all.

firaxis has control over direction of their own games though so i dont see a FPS of Alpha Centauri

Didn't Sid hint there would be a new version of Railroads?

I don't know, to be honest. But when it comes to Mircoprose transport management games, it's Transport Tycoon I'd love to see a remake of. That would please me greatly.

he's dropping hints lately that he's finally done a deal with EA to get AC and the other games they did for them back

There is Locomotion, the official "sequel" to TT(D). Same developer too.

You might like to look up the current code for openttd then... it no longer needs the old ttd assets (although you can use them if you have them) and it has many improvements (and features) over the original to improve it....
http://www.openttd.org/en/