A few months back, I wrote a blog about as you can see here.
Well, in the newer version of MSTSC for Windows Vista and Windows 2008, the "/console" option is no longer available. However, you can use a new switch "/admin".
This new switch has an advantage that "/admin" session can still be created when the session count has maxed out. Also, the "/admin" sessions don't count toward the session limit that may be configured on a terminal server to limit the number of sessions.