I installed Office 2013 only so I could get Lync.  I tried Outlook 2013 and decided that the change they made to remove bolded folder names for unread note notifications was just a bad idea.  I concluded that at this time, there's no reason to stop using Outlook 2010.  This was working fine for a while.  A few days ago I started getting an odd notification about a DLL being in conflict (I don't remember the exact message).  It also says that I need to reinstall Outlook.  I searched for this message on the net, and it appears to happen when you run Outlook 2010 after you've installed Office 2013.  Although this message is mildly annoying, it doesn't happen that often, and I'm not seeing any other symptoms.  Is there some risk in the long term in using Outlook 2010 with Office 2013?  Although I log into Lync, I'm not using it much yet.