Well, if you liked the first one... you going to definately like this one. I managed to get a copy of it a bit early (a sticker on it stated not to be sold until 11/18/2003). Of course, I haven't tested out the vs. play on Live! just yet, since it looks like it's not working (probably not until 11/18). However, it is kinda cool to see your name up there in the top 10 in the world (which apparently is working at this point on Live!). The tracks are much nicer... with more of a skyline than previously. The Kudo's system has been improved a bit... allowing you to gain Kudo's for being a good driver as well as pulling off some cool slides. It also looks like your ghost gets uploaded with your high score, I presume so that others can race against the top people. That's kind of cool. Can't wait to try racing with some real people... then I won't be able to say the computer cheats ;-)
[update] Multiplayer is downright addictive! You need to work on getting some of the cars unlocked though in offline gameplay so you can use them when playing against others. The gameplay is pretty rock solid. Only a couple of glitches due to lag, but they were extremely minor.