For release notes: https://www.vmware.com/support/player50/doc/player-501-release-notes.html
This is also (obviously, if you take a look at the associated ebuilds) going to require a bump or at least a change to app-emulation/vmware-modules, since it's working directly with a DEP on =app-emulation/vmware-player-4.0.x. I would also guess that new vmware-tools are available, but that one is less certain.
vmware desktop 5.0.1 ebuilds are moved to main tree from overlay. please test.