Performance issues due to Inactive Terminal Server Ports
This is an interesting post and although I don't have any direct issues of performance with any of my Servers I can see the build up in the registry as described.
If you make extensive use of DPR / TS sessions you might want to check this out
http://blogs.technet.com/b/askperf/archive/2012/03/06/performance-issues-due-to-inactive-terminal-server-ports.aspx