We all agree that Stronghold and Stronghold Crusader are fantastic games.
While Stronghold 2 isn't quite as awesome i still find it very enjoyable from what time i had with it in the demo. Unfortunately i've been unable to actually find the full game.

Any chance of it coming to GOG any time soon?

It could possibly come to GOG when Stronghold 3 comes out I guess, but considering the quality of it compared to Stronhold and Crusader, I wouldn't see the point of it making it to the GOG games list.

That didn't stop Empire Earth 3 though.

I only played the demo for SH2, but from what I saw, it had some cool additions -- I liked that maps would expand based on what objectives you completed -- but the AI seemed really broken. Like, I built a way up to the border of the enemy territory, stationed archers there, and just shot into it. WTF?

There is a DRM free Stronghold Collection that contains Stronghold, Stronghold Crusader, Stronghold 2 and Stronghold Legends that retails for $30, but I've frequently seen for less. I do wish the other games in the series would come to GOG though