Yeah, I just checked it out (had to wait until I got home from work) and it doesn't sound as great as it could have.
It's apperantly going to be laggy as fuck, you won't know who you're playing against (??) and there's no tauting or messaging between players.
However, if you're playing against someone on you're friends list, you can send them messages during play (saved to up, down, left and right on the d-pad) and you can see who you're playing against and it probably won't be so laggy.
Now this wouldn't be so much of a problem, but it's so harder to build up you're friend list than it is on the 360. Unless you know the person, you won't have them on you're friends list.