From my last look at Pentium Ms, they aren't terribly excellent when it comes to games compared to desktop 'competitors'. If you're using it as a business machine, then sure, the Pentium M 780 (2.26GHz) would definitely stack up well against a Pentium IV.
Graphics-card wise, the best to my knowledge you can get at the moment in a laptop is a 7800GT (available with Alienware systems US), which is subjectively reasonably lower compared to the 512MB GTX.
BTW, M 780s, 2GB laptop RAM, high-end notebook video cards are freakin' expensive, so if you're looking for a gaming laptop on a budget.. well rest assured you can buy a heck of alot more for a desktop. If you're just looking for a notebook as a desktop replacement for non-graphically oriented tasks, then there's definitely good solutions available.