As of today, October 30, Criterion's NFS Most Wanted is officially available online or in the shops in North America. The release for Australia and Europe is planned for November 1 and 2 respectively (although some shops claim to offer the game before those dates - may be worth a look).
For that occasion, here's the official launch trailer, in case you hadn't seen it yet:



Meanwhile, the first reviews are rolling in. At the time of writing, NFS Most Wanted (X360/PS3 version) has scored an average of 85/100, based on 20 reviews so far:
NFS MW on Metacritic