Hey sharifr,  We currently do not support this through the PowerShell API. Like you said, the best you can do it query the terminal servers directly.   Using a combination of Get-QVWServer cmdlet from the vWorkspace module and Get-TSSession and Stop-TSSession from the PSTerminalServices module, you should be able to implement this functionality. I realize there are some permission implications using this method because the terminal services cmdlets require elevated permissions to execute. You could setup a restricted PowerShell endpoint on the terminal services machines that prevented execution of anything except the two require TS commands.   That said, I'll make sure we get this request into the roadmap. It's certainly something we should support directly.   PSTerminalServices [URL]  Constrained PowerShell Endpoints [URL]  Adam
Within vWorkspace Management Console you can view all connected users.  I'm looking for a tie in to this API (see image) to allow us to use powershell or another script that an vWorkspace user can execute to disconnect/logoff all of their sessions..  [IMAGE]  Is this even possible without reverting to a Terminal Session/Logoff PScript that unfortunatly will poll all TS not just vWorkspace. 
Powershell tie in to vWorkspace API for user sessions?