There are so many things wrong with this...
The XBox 360 has 512 MB of SHARED memory, not 512 MB of video memory. As such you can use more memory for textures at the expense of less memory for the game itself, and slower access rates to memory due to having to share access time with the GPU. The PS3 uses 256 MB of dedicated video memory geared to feed the GPU as fast as possible. When more space is needed for textures, you can use DMA to transfer them from system ram to the video ram... it's pretty easy as most devs have done that with PC video cards for years.
AA is not a matter of "creative programming to utilize all 8 cores", it's part of the GPU like all other nVidia GPUs. You seem to have missed the info that the RSX in the PS3 is just a slightly customized version of the GPU on the nVidia 7800 cards. If devs don't use AA, it's because they personally didn't feel it was needed, or thought that AA would slow the game too much (AA is the biggest slow-down for rendering after resolution). Personally, all the gamers I know prefer speed to AA, turning it down or off when the option is available to get the most FPS from the game. I certainly do.
It was the PS2 that needed to use the VU to do AA. AA is also missing on the PSP, but can be "simulated" with a little extra programming. The PS3, as mentioned, uses a regular GPU and has no need for "tricks" to give AA. However, this does bring up one thing that falls under "tricks" - some companies are paid to make better versions of their game for one console versus another. MS is particularly bad about this, having money to burn and a long history of anti-competitive tricks. If I were to hazard a guess, I'd say MS drove a truck-load of money up to Bethesda with a request for better visuals on the XBox and Windows versions of the game. The simplest way would be to just turn off AA completely.

