It appears update KB 3075220 - part of KB 3080348 - just rolled through my session hosts over night and turned on the Network Level Authentication requirement.
I disabled the requirement by unchecking the "Allow connections only from computers running desktop with network level authentication" and it appears I'm back in business. Thanks for the early morning fire drill Microsoft.
MS15-082: Vulnerabilities in RDP could allow remote code execution: August 11, 2015
Vulnerabilities in RDP Could Allow Remote Code Execution (3080348)
|After KB 3080348 update loaded, the "Network Level Authentication" was checked|
|Unchecked the "Network Level Authentication" requirement|