This came from the myITforum SMS email distribution list. Credit to Richard Benfield for figuring this out and posting the solution to the mail list.
Here is the long and short of getting the SCCM vNext VHD Test Drive to work for Native VHD Boot:
1) Download the SCCM vNext VHD Test Drive from the following link (Note it is over 9.5 GB so it will take a while):
2) Download the VHD Resizer from the following link and install it:
3) Download all of the appropriate (Server 2008 x64 compatible) drivers for your model system.
4) Extract the contents of the SCCM vNext VHD Test Drive (Note the vhd is 20 GB, so it will take a while)
a. You only really need the two .\*.mht files and the .\Virtual Hard Disks\*.vhd file
5) Decide what size you want the VHD to be. (The actual used space is about 25 GB and you won’t want to cut it too close)
a. I decided on 50 GB for my use.
6) Use either the “Disk Management” console or the “Diskpart” command-line utility to shrink the volume in the VHD
a. You will need to attach the VHD, select the larger volume of the two, shrink it to the desired size minus 100 MB, then detach the VHD
7) Run the VHD Resizer and change the VHD to Fixed and the size listed for “Min” (again, this will take a while)
a. FYI, it sat there for a long time appearing to do nothing. I was convinced it wasn’t working and may not be compatible with 2008×64, but eventually it started cranking away.
8) You may want to move and rename the VHD. (I renamed mine SCCMvNext.vhd and moved it to C:\VHDBoot\)
9) Use the process described at the following link to copy the Windows 7 or Server 08 default BCD entry and point it to your VHD file.
10) Either change your systems SATA mode to ATA in the BIOS or inject the appropriate Mass Storage Controller Driver in the VHD image.
11) Boot up and choose the new boot entry from the menu.
12) Login and install the drivers…
That’s pretty much it, at that point you have a Windows Server 2008 R2 x64 Native VHD Boot system with SCCM vNext preinstalled on it for testing/demos…
Wally tells us about SCCM 2012 changes compared to SCCM 2007 in UI and SQL Replication, but also changes related to Application Deployment and Operating System Deployment.