I'd recommend to ZEN-style brood for a week and decide a few rather important things...
I. Do you really need a Notebook?
For about 1200$ you could get a decent PC Desktop with these or higher stats -> 2.66GHz/2GB 800MHz CL5 RAM/nvidia 8800GTS 640MB <- what would be very useable for gaming 'a little'.
II. Are you going to use Mac OS X at all?
Important question to ask yourself since especially the operating system is the very reason to get an Apple computer. If your gaming times in Windows via Bootcamp overweight - you never needed a Mac.
III. Finally if you have researched and brooded enough and find yourself bleary-eyed staring at the ready configured MBP in the Apple Online Store for the 247th time with a nervous finger to send the order...
You should ask yourself why you actually need the mid-range 15.4'' MBP and consider that the 128MB VRAM won't ever justify the much higher price, especially if you keep in mind that the 8600m GT is only running at useable clockspeeds in the 17'' MBP anyways.
Whatever - if you can live with a more easy-going gaming experience and you don't need all settings maxed out there won't be another 15.4'' notebook performing better then the MBP while still being a high quality system at the same time.
MBP 2.2GHz/8600m GT 128MB
Doom 3
Low: 169fps
Ultra: 92fps
F.E.A.R.
min/min: 222fps
med/med: 112fps
max/max: 36fps
3DMark: 2809 points
World in Conflict is running stable at 1024x768 under Windows via Bootcamp.
Here is what convinced me to choose a MBP as my single primary computer for work AND gaming ->
Oblivion.
Personally I still didn't order it though and hope for a tiny boost until Christmas