i think its about time to go for a quad core cpu, i know its going to mean a new motherboard and ram too but i dont know what i should go for? any suggestions on what would give me a nice peformance increase from what i have at the moment? 
here is my current system
Windows 7 64bit Home Premium
Intel Core 2 Duo E8600
HIS iCooler V ATI Radeon HD 5850
Corsair Dominator 8GB (4x2GB) DDR2 XMS2 PC2-8500C5 TwinX
Asus P5Q Deluxe
Corsair HX 850W Psu
Samsung SpinPoint F3 1TB SATA

here is my current system
Windows 7 64bit Home Premium
Intel Core 2 Duo E8600
HIS iCooler V ATI Radeon HD 5850
Corsair Dominator 8GB (4x2GB) DDR2 XMS2 PC2-8500C5 TwinX
Asus P5Q Deluxe
Corsair HX 850W Psu
Samsung SpinPoint F3 1TB SATA