The point is that Borderlands 2 is the absolute pinnacle of PhysX, which is arguably a bad thing considering how long it's been around.
Now, the PhysX in Borderlands 2 is very nice, it adds to the graphics very nicely, but everything that goes on doesn't really require a GPU to process it, it's all fairly basic stuff that we've been seeing in games separately for years without "PhysX". Take a look at the Frostbite Engine and all the physics effects it can do without running on the GPU.
It all could easily run from a CPU, but it's hobbled for CPU usage, when there's a GPU option available to exaggerate the performance numbers. Outside of that, very few games even use hardware PhysX, so arguably there hasn't even been anything for AMD to do.
On top of that, the ONLY reason AMD would ever have for developing a hardware physics API would be to add as a checkbox feature on the product packaging. Think about it, the reason why PhysX isn't even used much (and even when it's used, the features aren't ground breaking) is because the developer needs/wants to sell their game to everyone with a GPU fast enough to run it.
If features are implemented PhysX wise that are an integral part of the game, only nVidia users would be able to play it, and no developer is going to chop a load of their potential market off like that, which is why PhysX will never take off as a proprietary API, and it's also the reason why physics effects that would actually benefit from a GPU's extra power won't happen if/until an open standard of hardware physics is established.
But I can't see that happening. Physics effects will get better as CPUs in general get better, and developers have more power to work with in general unless a third party company steps in. PhysX really isn't the type of thing that should be owned by a GPU manufacturer because it's so open to abuse then. Think if OpenGL or Direct X was owned by nVidia.
As for 3D and AMD apparently can't be arsed, it's hardly that case at all. Every company knows proprietary systems don't last very long, what real incentive has AMD got to develop a 3D system when there are other companies working on it, whose software is hardware agnostic, it's not like they have 0 involvement, they work with the companies behind the software to make sure it runs properly. Proprietary systems only benefit the company in charge of them, and 3D vision from nVidia, whilst being directly supported by nVidia is doing the opposite of what you want. The best type of 3D implementation will come from a system that any hardware can make use of (provided it's speced to of course). 3D vision will at some point (which may even be now) hindering further developments of 3D on PCs if nVidia is paying companies to invest in it.
