When attemping to upgrade a shared DP in ConfigMgr 2012 you could possibly see the status hang for hours or even days. You will see “The item MIG_Job 16777217 has finished running” over and over about once per hour in the migmctrl.log on the 2012 server. Looking at the secondary site that is being migrated to a 2012 DP you see that the secondary site has uninstalled and it’s also been removed from the 2007 console. If you encounter this open SQL Management studio on the 2012 site. Run select DPID from DistributionPoints where ServerName like ‘%servername%’. (substitute ‘%servername%’ with problem DP) Take note of the DPID. Open the distmgr.box on the 2012 primary site server, in notepad create a file called DPID.DPU where DPID equals the DPIP you found in the SQL query. This will force the packages to be converted into Single Instance Store. This should allow the DP upgrade to complete.
This is a known issue and should be corrected in SP1.