Furthermore, to say that 64 bit operating systems and processors are currently only good for performance purposes, like graphics, you're obviously not paying attention to the rest of the world. Intel makes 64 bit processors. They're call Itaniums. Sun makes 64 bit processors: Sparc and UltraSparc. IBM makes 64 bit processors: the G5. Most of major manufacturers make 64 bit processors. So let's not pretend 64 bits is a new concept. Hell, the Jaguar and Nintendo 64 both had 64 bit processors. And yes, I believe those played games. In fact, with the exception of the incredibly late entry by Microsoft, the game console world has been going to 64 bits and higher for years now. I think the Dreamcast was 128 bit.
Now, to avoid the "but we're talking about laptops" spiel, let's talk about laptops. Truth: 64 bit operating systems do exist. Linux, Solaris, and even Windows have 64 bit versions. Furthermore, Windows XP 64-bit is right around the corner, with betas readily available. And, if I'm not mistaken, Far Cry has support for the AMD64 architecture. Not to mention, within a year, 64 bit applications and games will become mainstream, and to buy a 32 bit laptop now would be akin to buying a screaming 286 machine with the 486 machines being shipped out the door. (Wow, a history joke. Crack open your computer books, kiddies.)
Now, let's get to the slamming insults. Yes, Pentium 4s burn less power, but not without reason. Pentium 4s do less work. Intel, in their infinite wisdom, decided to ramp up the core clock speed until the processor almost fell apart trying to keep up with the performance that AMD offered. Meanwhile, AMD increase their IPC (Instructions Per Clock cycle), so their processors burn more power because they do more per clock cycle. Intel finally wised up with the Pentium-M, which is a "far cry" (okay, bad pun) from any AMD64 chip.
So, I would say, even if you want a screaming gaming system, buy an AMD64. Otherwise, within a year or two, your system will not only be obsolete, but not even able to compete with the AMD64 systems that are built and ready to go today. Mark my words.
EDIT: And I don't know about you, but I can't afford to buy a new laptop every two years because I wanna game hard.