I recently bought a Toshiba Satellite P4 laptop, which has a 533 mHz FSB - most portables are still at 400 FSB, and desktop procs are up to 800 FSB without overclocking - this determines memory transfer speeds, so is very important for any and allplug-ins etc -
However, most laptops are further choked by 4500 rpm drives, mine is no exception. This will limit track count in multitrack software. There are aftermarket drives, by Hitachi I think, that are 7200 rpm for laptops. Ive not looked into them yet, but that should speed things up some.
Hope that helped... Steve