Proxmox: Enable Beta (Testing) Repository Channel

Based on http://pve.proxmox.com/wiki/Package_repositories
To Enable the PVE testing (Proxmox testing channel) do the following:
vi /etc/apt/sources.list
Insert
# PVE packages provided by proxmox.com deb http://download.proxmox.com/debian squeeze pvetest
Then update the system by using:
apt-get update;apt-get dist-upgrade