Right, and even though honestly disc streaming along with the main ram bandwidth is enough for most applications (textures aren't as bandwidth hungry as some would think) prioritizing commonly used textures to be housed in EDRAM would be effective, but it depends on the game being developed.
They aren't using the EDRAM 'yet'. Many of them simply hadn't figured out what they were doing with the system, and Nintendo's tools weren't very good (you could argue even Nintendo didn't really know what they were doing with the system yet) when the current crop of games was released. Obviously there are a couple that use it lightly, like Shin'en's game and Trine 2. Just goes to show you that the indie guys were able to get more acquainted with the system in a shorter period of time than big house publishers. A testament to their engineering prowess.
Considering that most developers have let themselves become factory production lines I get the feeling they don't really WANT to learn architecture more complex than "let's just keep throwing a bunch of RAM at it!" AAA production has just become such a mess that even the SLIGHTEST deviation throws wrenches in their beloved plans. It's kind of sad


