Terminal Services Server Drain Mode allows an administrator to prevent new logins to a terminal server. It does allow current users to stay connected and even allows disconnected sessions to re-connect and continue working. The Drain Mode feature also works with the new Terminal Services Session Broker Load Balancing.
If this kind of functionality sounds familiar it may be because Citrix has been doing this since the pre-MetaFrameXP days… Great job Microsoft on only being 7-8 years behind!
This post was on the Microsoft Terminal Services Team Blog: