Considering the following question: http://www.experts-exchange.com/OS/Microsoft_Operating_Systems/Server/Windows_Server_2008/Q_27609475.html
Seems that the RDS trial period has expired but If go to The Remote Desktop Licensing Manager I can see a server activated and there is the following information:
(Under Version and License Type).
Windows Server 2008 or Windows Server 2008 R2: CAL per User of TS or RDS Installed.
(Under Licensing Program).
(Under Total of Licenses).
- (Only a -).
(Under Expiration Date).
I suspect that these licenses are Windows CALs and perhaps were not properly installed but I wonder why Windows CALs could appear inside The Remote Desktop Licensing Manager.