It's a pleasure to announce that the System Center Virtual Manager TechCenter has launched today, in coordination with the RTM announcement of the product. You can view the site at: http://technet.microsoft.com/scvmm/default.aspx.
You can join the Virtual Machine Manager community via the forum. Go to the TechCenter and choose the "Community" tab. The link is there, which will guide you to the forum. The VHD and trial software will be available soon. Visit the site often to check on the VHD and trial software availability.