hm...
Planescape Torment
System Shock (1, 2)
Deus Ex
...those would be my guesses.

You have clearly underestimated community zeal when it comes to mysteries and theorycrafting :D

I LIKE that, sounds so much better than "making stuff up and talking out your arse"

Didn't you guys make a guessing contest (from given hints) before announcing Apogee?
Oh, and today's RPS is talking about Ultima. Coincidence? I think not.

One spin is that Planescape, Baldurs Gate etc are being rereleased in retail right now. Would make sense for them to come to digital download platforms at the same time.

I think it is EA on board ... they didnt make that much of profit past few years as they used to do so it is logical for them to team up with GoG and sell the good old games and make a bit more money on them ... Steam and D2D are fine, but GoG has good reputation for old games already so they are the right choice for them ....

Also as part of the agreement all the fixing GOG do for EA to get the games running might then be ported to other platforms. Remember how Interplay games started showing up on Steam a few months after GOG? EA and GOG could have come to some agreement where GOG get the games first in exchange for making the games work on modern OS's. Minimum effort for EA and a good deal for GOG.

..The funniest thing is that we didn't plan so deep in details to make it such a mind blowing mystery.
the problem now is that there are so many expectations from this announcement that it is bound to disappoint the majority
I hope i am mistaken

Even if it is System Shock 2 and EA you can be sure SOME people will be disappointed. You can please some people...

Well, they're claiming its the biggest announcement yet. Given that they've already got some major publishers on board it would be pretty belittling to them if it wasn't something huge. EA does look less likely now though. But there are still many great candidates.

Too bad we didn't mention boxed physical games before we were told that we/ve nailed the answer somewhere before.;)

Yeah, I've thought about this too. I can imagine a bunch of GOG employees sitting reading through this thread, then looking at each other and go "Oh crap, people are going to be so disappointed when they find out what it actually is, aren't they?"
Sometimes, hype is a bad thing.
Of course, I still hope that it's EA, but I'm expecting to be disappointed. In which case I hope it's something I haven't even thought of, but will still think is awesome.

Since everyone else has had a guess, here's mine, based mostly on what I'd love to see appear more than anything else...
The banner's not just a space scene: it's an impending sunrise over a planet.
Or is it, perhaps, an impending sunrise over Planet? One of two more sunrises that day?
It's *got* to be Alpha Centauri. "eXpect the uneXcelled". A 4-X game, truly unexcelled, with Alien X-fire expansion.