@klarklar
I see a lot of technical comments like yours that are overly simplified and, with all due respect to you and all those who comments on such things, way off the mark! It seems like fans of a console would just dream up some wild capability based on a few marketing jargons circulating about. Who am I to say so? I worked as a software developer for a couple years and while I had not worked in the game industry, the basic science is the same for all software development disciplines. Those who are trained in computer science are also trained with the foundation of computer hardware as well. That said, I can at least tell you that most of your assumptions about the PS3 are above and beyond its practical capability.
Xbox360 and PS3 are supercomputers:
Both MS and Sony claimed that their consoles broke the Teraflop barrier, something that used to be in the domain of supercomputers. This is certainly a fantastic milestone for consoles, however every 2008 PC with a good graphics card will post the same or better number. And with ordinary PC having better specs, the "super" in our current gen systems is very ordinary and a thing of the past. For reference, the first super computer to break the Teraflop mark was the ASCI Red of 1996! Super computers of 2008 are measured in Peta flops with the top tier systems(IBM, Cray) posting numbers higher than 1000 PFLOP. 1PFLOP = 1000 TFLOP.
In theory it could actually avoid using ram, having 512 for back up
Supercomputers of this generation are not constructed the same as the PS3. Yes, some of them have 6000 dual core Opterons + 13000 CELL chips in the system among "other things". And these "other things" are the huge missing parts in your assumption. As a consummer device, PS3 and PS4 will need a lot of RAM. There is not a practical way to get around this.
360 works more like a single cored processor PC
You may have heard developers saying the 360 is much simpler to develop for compared to the PS3. This is not the same as saying the hardware is similar to a dated single core machine. The 360 CPU is a multicore chip and as such poses similar parrallel coding challenge just the same as the PS3. However, for being the master in making Operating Systems, Microsoft was able to use their expertise and hide a lot of multicore coding complexity in the 360 development tools. This and a couple wise hardware design decisions helped make developing for the 360 more straight forward. It is the tools Sony need to catch up to MS. This is easier said than done.