Misses the point of a worldwide social game.
I live in Australia in northern Queensland, and this game doesn't hit the mark for online gaming for me. This is a big problem. You have choices of only two servers use in playing - Europe and U.S. Thousands of kilometres for broadband to play a fast-paced game is never going to work optimally. If you live in Australia, I would recommend you give this game a miss. Guild Wars, although no where near as fast-paced, suffers the same problem with no local server so the pings are bad. Real Bad. Sometimes it goes fine, mostly it doesn't. Not a single race was completed in NFS World without cars randomly bouncing around the track because the information on what my opponents were doing wasn't quick enough.
I'm running an Intel Quad Q9650 extreme processor with 8 gigs ram, Windows 7 64bit and a Nvidia 470gtx video card. I can crank the visuals right up no worries without framerate loss and have decent races was when playing single player to practice. However, this game was never meant to be played single player constantly. Hence the dilemma. Single playing where A.I. cars move smoothly but misses the point of a social game, or multiplayer where real people's cars are usually warping around me because of bad ping rates.
You want a fun multiplayer racing game for the PC, get Burnout Paradise. Its not a new game anymore, but still have loads of fun with it and all the challenges. Need for Speed World is just not as much fun. Not nearly.