I'm a baseball fanatic, so keep that in mind...
This year's game is pretty good, imo. I think all the new "swing-stick" and "complete control pitching" (or whatever they are called) are freakin' useless. The stupid pitching thing has you move the right stick in various patterns to get the right pitches. I think that's retarded. I, personally, revert to classic controls and its fun for me.
They've finally added a full minor league system, which is what I love the best about it. Games/Playoffs/Rosters/Development, the thing this year. Took a few years before they integrated that into the game. I will tell you MLB 05 was the best baseball game ever. But 2K is starting to get to that, imo.