Thunder Monkey
Banned
Or a compromise. A split ram pool. As long as they don't skimp on either side, which is what hurt the PS3, I don't know why it wouldn't be the way to go. 1.5-2 GB of GDDR5 and 4GB of DDR 3 and I think they would be in good shape for a generation. I'd have to imagine developers are sick of dealing with the limited memory at this point. If there really is a huge discrepancy between MS's machine and Sony's, memory wise, it's going to cause issues for multiplatform developers again.
Unless the speed differences between them make up the deficit.