I dont know if Ive read anything directly stating AMD quad core will work on current AM2's, but I have read things stating that even the next gen processors (for socket AM3) are supposed to be backwards compatable to AM2 motherboards (only they lack in features like DDR3 and HyperTransport 2.0 that will come with AM3 boards). Intel Quad cores have been stated as compatable with current C2D motherboards, but intel has had more of a habbit of changing the required chipsets (I think that might have been what a previous poster was referring to), which means that although your new fancy processor "fits" into your board it doesnt actually work. AMD has been better at the long term planning for that kinda thing, meaning that you probably have a better chance of being able to make a simple drop in upgrade with AMD. All in all though, the C2D board will probably still last you a while, especially since its just come out, and they are the better processors in my opinion at the moment. Im going through this same debate (Ive been going back and forth for a month or two now, probably buying my comp in maybe 2 weeks or so) and I think Ive now settled on the Conroe being the best buy. It might not be the most futureproofed, but its pretty good, plus it seems like a little bit better of a chip for right now (especially if you want to OC it).