I doubt that Uncharted 2 couldn't be done on the 360. It's a great game, but there is nothing about it that is beyond the capabilities of the 360 or a PC for that matter.
Nothing is beyond the capabilities of a PC. The PS360 are already outdated if you want to put the PC against them.
However. The 360 couldn't really handle Uncharted 2 solely due to the DVD limitation. Uncharted 2 uses the full 25gb of a single layered Bluray.
Everything in the above post is opinion unless stated otherwise.