Hello Matt,  Last time you logged this issue, it runed out to be a problem with IPv6.  IPv6 had been disabled but AFTER an IPv6 address had been registered in DNS.  What would happen is the RDS would get the IPv6 address for the Connection Broker so effectively couldn't check how many licenses were available.  Removing the IPv6 entries from DNS fixed the issue.  Thanks, Andrew.  P.S This is one cause for the issue - there can be more reasons ! 
I have a customer that has a 7.1 environment that consists of a Windows 2008 R2 server running the broker service and a Windows 2008 R2 server running the RDS role. The environment is licensed with a 5 User Enterprise and EOP license, however when they connect to an RDS session it goes through the logon process and then displays the 'License count was exceeded' error although know one else is logged on. I have see this before but can't recall the fix, I also search SupportLink with no success. 
License Count Exceeded