The NFS series will go through an evolutionary step with NFS:U 2. Not only will it be filled with cars you'll never own, now they're promoting it with a girl who wouldn't give you the time of day. Aah, progress.
On a slightly more serious note, I'd agree with most of the suggestions here. I'd especially agree with rubber-banding...at the very least, it should be an option, as it does make things a bit easier for new players (not having other racers be waaay ahead of you). However, for skilled players who've earned what should be a 45sec gap, or have worked to finish all the tracks on Hard (which should be a viable route: if you play against tougher opponents, you get better gear) they should be able to enjoy their lead and not worry about hyper-accelerating computer players who are always dogging their bumper.
I still love the pure racing goodness that was NFS:SE, to be honest. While the cops vs speeders thing was great for multiplayer, it could get annoying when you just wanted to race. That and it has the most enjoyable incarnation of the Dodge Viper I've ever had the pleasure of driving. NFS2 was a good game (I got it with my 3dfx Voodoo2

), but more of the same. The career mode from NFS:HS sucked, and HP2 was just lacking in direction. Porsche Unleashed was a great game, but lacked the interesting variety in vehicles (unsurprisingly) that I liked. Underground is a different direction, and one that I'm not all too fond of. While all the games were arcadey, this seems to be taking it too far, and foregoing an interesting racing game for flash and glimmer. Hopefully they'll add more of the most-loved and most-requested features from the other NFS games (aren't they supposed to IMPROVE with time?), along with more variety and more real choices throughout the game.