It is not on xbox live. you can play it with XBox connect, but the lag is always a problem. The game wasnt made to be played online, which is probably why they never made it possible to play on live. The average packet size is too big.
If, for some reason, it was created to be online playable, It would be amazing and I would play everyday.
[Edited on 09.26.2010 2:59 PM PDT]