Haven't seen this posted but it seems that someone's hacked the PhysX drivers to re-enable physX when AMD cards are detected
http://www.ngohq.com/news/16560-patch-re-enables-physx-when-ati-card-is-present.html
http://www.ngohq.com/news/16560-patch-re-enables-physx-when-ati-card-is-present.html