Today the developers, Firaxis, has posted this video look of the game, giving us the first chance of actually seeing it in action:
I'm personally really excited after watching this video!
Some people may disagree with the somewhat cartoony art direction that the game seems to be sporting, but I don't mind it at all, and I think that the new "glamour" cam that they were showing off looked awesome and will help add to the immersion of combat.
I'm definitely much more interested in XCOM: Enemy Uknown now and looking forward to playing it later this year (no firm release date is available yet, though).