yeah given the main difference b/t whitebook and the aluminum is just the ram speed I can vouch for the following on my 2.0 Aluminum MB:
Left 4 Dead
Call of Duty4
The Orange Box (HL2 etc)
all run very well, prob CoD4 the weakest of the bunch but can run at 30+ by turning off various settings like smoke, that reflective one and a few others. You'll be satisfied! This is from specs in sig on XP32bit.