I'm happy to hear talks of Memory. I'm hoping they bump up to basic computer which is 4gig.
I would be happy with 1.5GB of RAM, there is no way 4GB is gonna happen.
Console RAM is much different than PC RAM in that it has lower power consumption, lower latency and things like that which make it more expensive than the store shelf stuff you would buy for your PC/Laptop.
I think Sony may be the only one crazy enough to attempt (anything near) 4GB RAM, but that's only if they want a $600 system again. Even still, I wouldn't expect any next-gen system (720 & PS4) to go higher than 2.5GB (most likely 2GB) in several different layouts.
It all comes down to efficiency, and with no bloated OS and dozens of background apps to run in the background, there really isn't a
need for 4 GBs of RAM in the next gen systems.
Unless of course Sony really is trying to support 4k resolutions... and then 1 up Nintendo on the Tablet controller front (4 streaming HD controllers) while also trying to be a HTPC and a set-top box and then improve upon Move & Kinect and... and.... and....