Microsoft unveiled a new Xbox 360 S console at E3 this month, and without delay the new machine has been dissected and tested. The most dramatic change is the move to a single-chip CPU/GPU hybrid processor that is apparently being built on the 45nm process technology from GlobalFoundries, AMD's spun-off production facilities. With the inclusion of the new processor, the Xbox 360 S uses much less power (about 30-40%) compared to previous generation machines, and also turns out to be much quieter as a result of a single, larger fan. This article has photographic evidence of the teardown, with comparisons between this Valhalla platform and the older Falcon system, along with videos of the reconstruction process and noise comparisons."
The new console also takes measures to protect itself from overheating, so RRoDs shouldn't be a problem with this revision.