Re: New notebook...buy now or later?
Core Duo draws so much less electricity than the Pentium 4 that Centrino based laptops offer battery runtimes that are up to twice as long as those of P4 based systems. Centrino laptops need much smaller battery packs to power them, which makes them much more compact and lightweight than that of P4 notebooks. Beyond that, the Core Duo equipped notebooks also generates very little heat, which means the fans on a Centrino laptop won't kick on very loud or very often, unlike the distracting fan noise that often comes from Pentium 4 laptops.
Since you are gaming and need all the performance you can get, just get the Pentium 4 then. They run hot and they're bulky though. I feel the Centrino Core Duo are just as capable of gaming, besides the point of being dual core and all.
*Fact: Microsoft Window's Blue Screen of Death vs Computerforums.org's White Screen of Death. Which is worse?