Yeah, Conroe pawns everything AMD has by a long shot. The AM2 architecture uses DDR2 as well, but its just not as well developed as the Conroe. Conroe's big L2 cache, also helps it crush AMD's attempts to maintain their iron fist on the tech world. Lol, yeah your current build looks good. What are your current specs, anyway? If they're similiar to your new build, just save up for the Conroe. It'll be a better upgrade, down the road.
Oh yeah, the Conroe is LGA 775 socket, but the Conroe is a 65nm cpu. It just won't work with current mobos. You'll have to buy a completely new board for it, in case you didn't know. Good luck, and hope you have fun with your build.