Worst game in the series! Absolute terrible bias shown to people who spend money online to improve teams.
The major problem with this year's version is that you can literally buy improvements for your team online! These are the sort of things that should be mandatory for a player to earn while playing the game. This literally gives players with more money an unfair advantage.
The running game is the same as always. The passing game is also the same in terms of throwing and catching. Defense is the area where there are some slight modifications. It is now more difficult to intercept a pass, which I believe is a bad thing. Last year if you threw up a ball on a fade route and the pass was a "jump ball" it would be intercepted almost every time if you did things the way you were supposed to. That was realistic and cool. This year, the gameplay isn't nearly as precise. Sometimes your DB will even swat the ball, and it will get tipped in a way that causes it to be caught by another receiver, which truly represents terrible gameplay.
As far as the replays go, this year it isn't nearly as good as last year. This year it is almost as if you are watching prerendered "video" running at an unsmooth framerate. Last year it was so much more impressive because you could watch the cheers in what was clearly live polygon action. It's almost as if EA tried some sort of new graphic technique or had a different development team working on the game -- sort of like what Activision does with both Infinity Ward and Treyarch working on Call of Duty games that are released every other year.
Overall, I'm very disappointed with NCAA 2010. If you own NCAA 2009 there is virtually no reason for you to buy the new version. You will only be disappointed, and you will probably be mad when you realize that people who spend more cash online will end up with advantages.