Pretty good, but it's not brilliant. Then again, I'm one of those people who think the original game was over-hyped.
It seems like the original game in terms of feel, only now there is a lot more chatter from your squadmates, which is good. The AI on them and the enemies seems good also. They put in a grenade indicator, indicating where thrown grenades have landed, giving you an opportunity to get out of the way. Quite handy.
There's no health bar, so it's hard to tell how much health you have left; the game tells you to find cover when you've taken a bunch of hits.
There's no in-game save, but the game auto-saves at regular intervals.
They talked a lot about how COD2 wouldn't be as linear as the first game, but this level wasn't a really great indicator of that. It's pretty straightforward.
As with the first game, there's lots of scripted stuff going on; planes flying overhead, stuff blowing up, etc. Most of it is done fairly well.
Performance-wise, it ran well for me at 1024x768 with AF on and high detail settings; a little bit of chop here and there, but nothing major. Then again, I only have a 1.8GHGZ processor.
Not mind-blowing, but it's good. Pretty much what you'd expect a COD sequel to be like.