A few weeks ago Cisco revised their release notes for the Nexus 1000v 4.0(4)SV1(2) version. This is not a new version of the 1000v VSM appliance, just updated documentation. The updates clarify limitations with vMotion, VMware Lab Manager, ACL limitations, and NetFlow limitations. You can check out the new release notes here.
The good news in the revised notes is that vMotion of the VSM is now fully supported. However, you don’t want both the active and standby VSM on the same physical ESX host. Makes sense!
Cisco has released an updated 1000v download package, which appears to have an updated VEM component. The VSM component remains unchanged since the original 4.0(4)SV1(2) release.
You can download the updated installer package here. If you just want to download the latest VEM, you can get it from VMware here and selecting VEM from the drop-down. VEMs seem to get updated in conjunction with each new public build of ESX(i).