The writing was slightly on the wall with Mirror's Edge adding PhysX prior to release next January, so EA announcing that it has licensed PhysX to be used as a development platform in all its worldwide studios isn't that shocking. Less predicable, though, is 2K Games' announcement that it will be doing the same.
Despite its relatively prolific use for consoles, PhysX hasn't really taken off so much on the GPU-accelerated PC-centric front. With two developers, especially two such large (not to mention prolific, EA) ones on board promising to have all their dev teams using the PhysX SDK that should change. If nVidia can persuade the public that PhysX is more than just a value-add proposition, and in fact a 'required' aspect of the game it should mean good things for GPU sales!
It will definitely be interesting to see what AMD's counter to this is. There has been the promise of AMD and Havok working together for some time now, but to no apparent avail. Perhaps EA and 2K's decision to back PhysX will prompt a reaction.