It's highly improbable that would happen if AMD took over ATI support for PhysX. But then it's highly improbable that AMD would be interested in doing so. So it's all just speculation and subsequently not very purposeful.
Whatever the case, an open source solution might be the answer.

Wait wtf are you going on about here?? it makes no sense.. if a company took over one of its departments work it would work better than if it let the experienced department keep working?? but then again ATI support for physx isn't ATI's job thats the job of you know the company that makes it that being nvidia,
Navagon AMD CAN'T write physx drivers that would be you know... ILLEGAL? ATI did approach them thats a matter of record they ended up going Bullet and Havok. Now lets have some fun shall we..
[url=http://www.realworldtech.com/page.cfm?ArticleID=RWT070510142143]cripples physx.
Add that they are SO anti others that if you have an ATI card in your system it wont run physx and as I've personally discovered that INCLUDES on board graphics I have a 9800 the card recommends be used as a second dedicated physx card and i'm told i have no compatible card and it runs in cpu mode on batman and other physx games.
Yeah they really want to let others use physx eh?

Lol! Thanks Kabuto! :)

Have you asked yourself why Nvidia wants ati to make physx supported cards? Not from goodness of their heart, not for your or mine benefit.
There is only one reason
Money.
Ati, Nvidia, Intel, Valve. Their one and only one concern is money. You are kidding yourself thinking anything otherwise.
Nvidia belives that Ati support of Physx will bring them more money... I told you why. Greater market control, will make ATI dependable on Nvidia.
Valve is doing the same thing with steamworks. Making game dependent on steam gives them greater control over the computer game market. Some game became even steam exclusive... (non-valve games).
With Nvidia it is even more pronounce because they are public company. They have to answer to shareholders.
It is simple: AMD supports Nvidia's product, great probability that it becomes market standard. If that happens AMD graphics department is controlled by Nvidia. And that's a big no for AMD

but... but it is fun...
AFP already got his answer :) :)

I've used nVidia cards since the TNT2 Vanta (pressed by Creative Labs Tech), but lately...
nVidia are starting to resemble 3DFX, the company they bought out for their SLI technology. That is not good. 3DFX went all proprietary and got swallowed up by nVidia. Same thing happening now. I'm glad AMD is not giving into PhysX. I feel nVidia should have left Aegeia alone. They would have eventually gained a following and shared it with both companies. BFG ended their GPU offerings because Fermi was too late, not as advertised and poorly offered. BFG literally starved to GPU death waiting for its partner to make good on its promise. XFX now makes Radeon cards more than they do geForces.
If EVGA and PNY decide to start pressing Radeons, nVidia will need to worry.
You can still buy PhysX cards on eBay in PCI or PCIe form. Pair it with an ATI card and it should work as advertised. After my 9800GTX OC+ 1GB has had its run I am going over to AMD GPUs. I've supported AMD's efforts since they originally released the Evergreen 133mhz overdrive processor for the Intel DX2 66 CPU (1998).
You folks buying Fermis, I hope you're happy knowing that nVidia are not above screwing over their partners (BFG)
And to think I used to own stock in nVidia.

Why do you need a computer? If we know what it's for and what it needs to be able to do then we'll can do a much better job of giving advice on what parts you'll need. Otherwise we'd be just guessing really.

Not much really. Old games. (Freespace Open, and Homeworld 2 are probably about as graphics intensive as I'll get.) Surfing the web, just things like that. One big thing, is if it doesn't come with an OS I'll be using linux. So 3D acceleration needs to be supported under linux with whatever card I use.
Now I did see the "Gaming computer for under $400" here: http://www.hardware-revolution.com/400-gaming-pc/
That might be what I end up doing, the only thing is does that Radeon HD 4670 work under linux?
I just found this: http://en.opensuse.org/HCL/ATI_Video_Cards#Radeon_HD_4670
According to that it's fully supported. Now will that be true under any linux distro?

This is not "entirely" on-topic, but one thing bothers me a bit. Does it matter if the power supply-thingie in computers is upside down? I mean, can it be installed both to the top of the computer case and bottom of it?
Hope you understand what I'm asking here, since I have some trouble explaining it in english..
Long story short, is it possible to install it either the fan facing upwards or downwards?

yes it's possible no it's not advised plus moding a case to accept it isn't the most fun thing in the world to do