First off, NHL 09 is hands down the best hockey simulation I've played. So for EA to top this with NHL 10 would be very difficult. That being said, NHL does have some enhancements that improve on the predecessor. The first person fighting is more realistic. The passing is a lot harder and takes getting used to, but now you can use the boards to pass the puck. NHL 10 has a board play feature where you can pin the puck to the boards and kick it to you teammates. As always, the online team play is the best feature of this game. Having 6 guys play on a team is unreal. Another feature is the penalties after the whistle. I was all for guys getting penalties when you get run over after the whistle in NHL 09. But in this game, after the whistle, the play can go on for 20 seconds with no penalties being called. It just seems to drag out the game, when all you really want to do is get back to playing. You can boost your players abilities by playing games and keep your grade at a certain level. This would include stick and skates. This year, you can use microsoft points to make your player better.
So if you're the casual game player, then nhl 09 is all your need. But if you're hockey fan, then this game is for you.