I posted the other day about a hotfix that's needed after you apply SQL Server 2012 SP1 CU3, to still be able to open or edit SSIS projects or database maintenance plans in SSDT.
However, I found that after I applied CU3 and the hotfix, that all my stored credential details for SQL Servers was gone. That was particularly nasty for all my Azure-related logons. I had to set them up again.
No idea why that happened but figured I should give you all a heads-up about it!