Revolution's GPU is called Hollywood, and I highly doubt it is ATI's M28 GPU with 1T-SRAM.
Hollywood does use 1T-SRAM but it's architecture is probably very different from M28. as far as I know, it's only been confirmed that Revolution's GPU will use 1T-SRAM, not the main system memory, which could be GDDR3 or something else. however, I do think there's a good chance of 1T-SRAM being used as Revolution's system memory, because of backwards compatibility issues. I am not sure how GDDR3 would play out in Revolution, with it having to run Gamecube games--I am thinking in terms of latency. whatever Revolution as a whole has, it will cost less to manufacture than either PS3 or X360. I think Revolution will offer comparable in-game visuals to the other two consoles at 480p, even though Revolution is claimed to be not as powerful technically. CPU-wise, I expect Revolution to be the weakest, but I think GPU wise, Revolution is going to be close to Xenos and RSX, especially since, like Xenos, Hollywood will have embedded memory.