As I stated before, I heard rumors that the PS4 would be using 4D stacking. It was from a really reliable source. He said Sony would stay with IBM, but everyone here is claiming AMD so I just accepted that.
I was researching 4D stacking however, and guess what turned up:
http://www.google.com/patents/US20110170266
It appears that the 4D stacking method is patented by IBM. In that case, I think we can expect the PS4 to carry IBM hardware, maybe alongside AMD GPU's, and 4D stacking as well
edit: OMG :-0
looks like we have a winner.
I am betting my 360 that PS4 will be 2GB, 4D stacked, Cell2
I remember you or someone else saying something like this but I thought it was just a joke so I just ignored it.