Quad core Q9550 for GTX 285 ?

My system: E6850 at 3Ghz, Asus P43 mobo, 4 GB Kingston 1066, Gigabyte GTX 285 1GB DDR3, Zalman 600W psu and windows vista 32.

My question is if the cpu is bottleneck my system. I play all games like Crysis, Fear 2, Far Cry 2, Company of heroes, Gothic 3, Assasins Creed, etc... My monitor is 22' and i play at the resolution of 1650X1080 with full details. Except Crysis (41 fps) all the other games i have over 50 fps. I have seen i a lot of reviews that my GTX 285 can go faster with another rig. Is the cpu the problem??

My second question is if the new games that will come like Diablo3, Starcraft 2, Aion etc...will play over 40 fps in my computer.

Is it worth to change my current cpu with Q9550? Am i see any difference? Or even should overclock my current at 3.4Ghz (i am afraid alittle   )

Thank you

P.S. sorry for my poor english...