Exchange 2010 EMS, fail, fail, connect
If your Exchange Management Console PowerShell shortcut (EMS) opens and tries to connect to a CAS multiple times, fails, then retries and succeeds.
[Immediately] suspect 'cruft' from add-on modules in the IISAdmin > Content > Explorer for the virtual folder for PowerShell in [web.config]
In this case it was leftover from an uninstalled module for Advanced Logging applications.
Exchange apparently timesout trying to load the module, or has other quality problems with the module and fails, it returns and randomly can eventually 'silently' fail to load the module and continue to provide a prompt.
But this can very confusingly and maddeningly leave you wondering why its taking so long, and there are [no] Event, IIS Logs or any other indications of problems.
I've seen this exact same thing in other contexts.. lesson Exchange depends on IIS but the bridge is very tenuous.. neither side appears to support the other very well with diagnostics.