There are a few problems with multiplayer as I see it. Fine, you can have a PPU enabled server, and then everyone gets the benefit of the heavy lifting done server side, but that does mean all the client side effects are inconsequential, because they have to be, or the game is not in sync.
Given that people tend to turn off high end detail in online games to improve their frame rate, there is really only justification in the servers being PPU enabled.
Now for single player, you come back to the problem of having to support both those that have a PPU and those that don't, and physics isn't really like rendering, you can't really have the equivalent of LOD, you have to run it all or you end up with weird stuff like boxes that float in mid air until the player comes in range, and then they suddenly fall to the floor, etc.
So given the need to run physics constantly and support those without a PPU, how can you have a compelling PPU demonstration game. It's either just fluff (loads of crap to knock over, that you leave out if no PPU is there), or it runs like a dog if you have a load of really useful physics stuff, but no PPU.
Seems like in the end you'd really have to produce a game that was PPU only, if you really wanted it to show its stuff.
I think I've worn out my P and U keys.
This comment was edited on Dec 19, 22:16.