I think, at the moment, this is the only one. Coincidentally I bought Fruit Ninja a couple of days ago, and now with this update, I really look forward to trying out multiplayer (unfortunately my other iPhone friends still haven't signed up to Game Center.)
Fruit Ninja multiplayer is really fun BUT it has one VERY annoying characteristic!
Basically if you tend to win most rounds you will probably know what I am talking about. Start climbing ahead in points and all of a sudden all that seems to pop is your opponents fruit, big clusters of them, until their score is back to where yours is, at which point the game starts popping a more equal selection of fruit again.
Its like some racing games where it assists the losing driver by making his car catch up to the winner more easily.
It does it without fail every time to the point where I have sat there laughing and thinking "WTF?! this is pathetic!". I still win most games of course for I am the almighty Sir Ruben and you can bet I will snag that rare +3 fruit before you do. Thats what being a fruit ninja is all about