there's no reason to make PC version crappy, to fit PS3. they can just downsize textures for PS version, and reduce poly count.
You can usually do such things in graphic settings. So PS could run on mid settings, and PC users could crank up settings to max.
We'll just have to wait and see what settings beta has, or at release; and it's possible they didn't go overboard with graphics, cause they waiting for the DX 11 patch.
Otherwise hopefully there will be able to be graphic mods

Well if grass looks so pixely, then it will make much of the environment look pixely. Then you would need to use high Anti Aliasing settings...which lags the game a lot; or it will just look low quality.
But i think mostly they just need higher res textures, that don't look like lego-structures at close up.