One thing to think of is: Even if a game only needs 4 GB of ram, it would still benefit of the increasing from 4 to 8 GB. It's the same reason why you won't put a single 4GB bar of RAM into your pc if you just want to have 4GB. you'd take two 2GB bars, because they together would be faster than one alone.
Paired with the fact we will see GDDR5 i think the main benefit should be faster loading times. better textures of course, but the loading times should do very well. maybe the next elder scrolls isn't that annoying when entering stores and stuff.

must-have-list for platforms i don't own yet:
WiiU: Donkey Kong
XBone: Dead Rising 3, Ryse







