The Inquirer writes AGEIA and its retail partners begun sampling their PhysX cards. It won't take long before we'll see the first reviews.
We know that the driver weighs in at some 8MB, but we are sure that it includes some API things that will make your card run the super-cool physics.
The cards can be pre-ordered at a few places and should hit the retail with a $250 suggested retail price. We know that the cards and drivers are ready as guys such as Dell, Dellianware, Falcon Northwest and Voodoo PC have been shipping OEM versions of those cards for some time.