Tom's Hardware Guide managed to get its hands on a laptop PC based on Intel's new Banias (Pentium M) laptop with a 855 chipset (the whole package is called Centrino). They've benchmarked it against a Pentium 4-based laptop in a range of power conservation modes (including "all out" desktop mode), and they've tested battery life, as well. They don't have a lot of information about Banias, but this new processor appears to be a very different animal from either the Pentium III or Pentium 4though it may incorporate elements of both. Anyhow, at 1.6GHz, this chip is a very respectable performer, keeping pace with a Pentium 4 2.2GHz in many cases.
I'm intrigued to see how Intel sells a high-IPC processor to the world without all but outright acknowledging the validity of schemes like AMD's "model number" rating system. Unfortunately, the THG article doesn't have much to say about that.