I'm not sure there'd be a benefit on console of 4 GB over 2 GB. Even PC only games rarely go over 2 GB of system memory used.
Hmm, than again. If memory is still being shared between GPU and CPU, 3 or 4 GB would probably be better.
Also for assets that would actually use that amount of memory, we're going to have to have mandatory full HDD installs with nothing streamed from disc except for Movies. Otherwise level loads will be intolerably long and if the game streams world data, pop in is going to be huge and/or art assets will be lowered. Even on PC with fast 7,200 or 10,000 RPM drives, there's still noticeable texture pop in with texture streaming engines as well as relatively long load times for games that actually include high resolution/high fidelity assets. I'd hate to imagine high resolution gameplay with high quality assets and being constrained to the speed of an optical drive. /shudder.
This also means no 2.5 inch mechanical HDDs. They'll have to use 3.5" drives or SSDs. Otherwise the drive is going to become a very serious bottleneck in the system.
This is, of course, assuming optical media is still being used for distribution.
Regards,
SB