Hi,
I installed VS Update 2 RTM on my dev machine which has SharePoint Server 2010, Visual Studio 2010, Visual Studio 2012 and Visual Studio 2013 installed.
I can't deploy SP 2010 solutions from the VS 2013 after the Update 2 because VS says that "required version of SharePoint 2010 is not installed" yet SharePoint is working just fine.
When I remove the update 2 then the problem disappears. VS 2010 and 2012 are luckily not affected by the problematic update. So there is something wrong / untested in this update.
Can someone confirm / replicate?