Also, there is a smaller indie game called Xenonauts coming out in october also that is much closer to the original X-Com to also check out.
There was a thread on these forums about it, but the game's page can be
found here.X-Com:EU is something I'm looking forward too and will probably be grabbing, but it is very much a re-interpretation of X-com and is not really that close to the original game.
Xenonauts is essentially X-com updated and made to fit the modern gaming environment while still being as close to x-com as possible.
The biggest thing I'm noticing so far, having only played the X-com:EU demo and not played Xenonauts at all is that X-com:EU is a faster paced game where you move you men forward using cover and trade shots with the aliens, with the cover keeping your men alive if you've done it right.
Xenonauts is going for a slower paced game, if you rush forward and trade shots the aliens are pretty much guaranteed to win, even with cover. Rather, you have to position you men correctly to overwhelm the aliens with numbers as they are simply better then your men 1v1.
I'm looking forward to both and we'll see how they actually turn out once released.
D.