For those that may not have yet heard, the SCCM 2007 R3 beta is available for folks to look at if they are interested.  I’m in process of setting up my own test box to play with it.  It is an open beta program and eval version, so you can only apply it to a SCCM eval install, not to a full install as most folks have.  The good news is that you can download a VHD of SCCM 2007 R2 eval and then apply the SP3 to that and play around.  The VHD and other R3 info is at the open beta section on Microsoft connect (https://connect.microsoft.com/site16).