As for other virtualization products, I tried in inside an OpenVZ setup (Proxmox 1.6). A container almost took down the hardware node. It was very slow, although responsive. "vzctl stop" timed out. Just a reboot brought back that machine. Therefore, I am living under the impression that any container based virtualization technology is vulnerable due to the usage of the same kernel for all the available virtual machines.

Proxmox ran inside a VirtualBox instance. All the allocated memory to the virtual machine was taken by the exploit. Even more, after rebooting the VirtualBox machine, it leaked the whole memory used by the affected Proxmox. The only way I could get it back was to stop the VirtualBox machine.