Pentium M seems to be the most balanced current laptop processor. i.e. good performance, low power, flexible speedstep technology, long battery life.
The downside is the price, but there are some Celeron M chips that despite 'only' a 512k cache, offer good performance. Mobile Celerons are usually closer in performance to the desktop equivalent, than the desktop Celerons are. It seems to be true for these chips also. When Pentium M finally moves to 533 FSB though, the gap between the two will rise of course.
The benchmarks on the link below compare Banias, Dothan & Celeron M, but only against Athlon 64 and Pentium 4. If you know how an Athlon XP compares against either of these two, you?ll be able to extrapolate a relevant conclusion.
The mobile A64s sound great chips, and I?m referring to the lower voltage XP-M equivalents, which aren?t called 64-M, so they?re a bit harder to identify.
I don?t know if mobile Semprons will be available in both SoA and S754?
Intel's 90nm Pentium M 755: Dothan Investigated