[hellsing9]

It's almost PC gameplay with the render-ish style of PS3, don't know the specs used to run the demo.

But as far as we know we have many upcoming engines that will be *better* for pc gamers than the *old* UT engine.
You have:

1) Crytek
2) Fox Engine
3) UT the 4th gen one.
4) Frostbite 2.0

If they are well optimized i don't think you will need a super high-end computer to play this. Btw i don't know if Kojima in this case went some steps ahead for some particular *reason* or just to get a smile on PC users even with not official confirmation of something being released on PC with FOX engine.
But we all know how Crysis engine (the first one) was a pain to run in any rig.

(An example of good optimized engine: Dead space series)

As for the PS3 exclusive content, that's really a big letdown.
The day i see MGS4 ported to Microsoft i will be mad as many others MGS fans.