Meh, NV are buying them for the software/engineering resources it will probably be at least DX11 class hardware before you see anything dedicated to physics. Could be useful for something like a Playstation 4 many years from now.
In the mean time Intel's Larrabee project is rumoured to be more a true general purpose GPU and probably handles physics just as well if not better. Imagine a card were Direct-X just becomes an API no need to change hardware, the only reason to buy a new Larrabee is because it is faster than the old one just like a CPU. If that were true that would be a big boost to PC gaming by removing another technological stumbling block.
Anyway I think the whole physics is just a big pile of hype, the vast majority of PC gamers wont be running cutting edge GPU's that can do insane physics, the biggest selling PC games are the Sims and World of Warcraft which are hardly in need of such fancy effects. Most PC's will have a dual core CPU and developers would be better spending their resources targeting that than a proprietary GPU system owned by a small group of PC enthusiasts.
If anything AMD was smart to not buy Agiea they already have very capable physics on GPU's via their own GP-GPU API, it's also an area NVIDIA's GPU's have been "less effective" at due to the architectural differences.
Plus unless Microsoft steps in which they may not want to (anti-trust getting sued etc) a lot of devs prefer to roll their own physics or use middle ware so without some form of standardization GPU physics just like it is now will go nowhere.