The references in the article are pretty damn wrong. In terms of raw GPU horsepower, a Radeon 7970 (The most powerful single-gpu card on the market at the moment) has about 7 times the processing power of the one found in the 360 (And given that the PS3 GPU comes from the same generation, the same is true there).
However, that's not the problem.
The problem with emulating modern consoles (or any console in the history of ever), is that it's not enough to just find a way to make the binaries run on another hardware, you have to find a way to accurately emulate the actual hardware and its quirks. Modern console programs are heavily optimized for the hardware they are running on; if we take the PS3 and Uncharted as an example, Naughty Dog are using several of the Cell's SPUs to offload postprocessing duties on the fly. This is something noone would ever do on a PC, and a case in which a direct translation of the process to the PC architecture would incur slowdowns like crazy.
Right now, we're just about able to emulate PS2s, 12 years after that system's debut. Because it took that long to reverse-engineer and recreate the internal workings of the PS2 to a degree where emulation is mostly stable. Getting to the same level with the PS3 and 360 will take quite a bit longer.