revision, a couple limited editions, and even a new SKU, it looks like Microsoft is finally shipping "Falcon"-equipped Xbox 360s with 65nm CPUs. According to the eagle-eyed posters in the official Xbox forums, Halo edition 360s from lot #734 appear to be the first machines with the new chips, and the time-honored method of peeking inside the case with a flashlight should confirm you have the latest and greatest once you get your baby home. Check the read links for tons more info (and a fun little flamewar).
[Image from user JWSpeed in the Xbox forums]
Read -- Original thread with pics of the new chipset
Read -- What to look for to see if you've got a 65nm 360