"I doubt memory yield are high enough for that to happen. Memory prices would be way too high and there would be less memory for video cards."
Didn't nVidia announce that they were hoping to use 300/333/400 DDR on their next product? (The GF3U/GF4 or whatever is next)
"Well the reason I say that is that I read somewhere that Intel is coming out with a 400Mhz bus for whatever reason, I doubt AMD will sit by and let that happen with out some kind of update to its(or VIA) chipsets. "
It isn't 400MHz it's equivalent to 400MHz is double width double edged transfers (4x100....hence being called Quad Pumped).
Thorin