New release of PhysX System Software - PSS 9.12.0807 – has been spotted in MSI 306.38 Beta GPU drivers.
Official Release Notes are unknown.
However, we have discovered that .0807 release only contains libraries for PhysX SDK 2.7.x and above – probably, it was done to reduce size of the installer. At the same time, this makes new PSS incompatible with old (2005-2007) PhysX based games.
Thanks to Spets for the link.