If you are a current user of GPS Analyst Extension for ESRI ArcGIS desktop software then you should not update to the current release of ArcGIS v10.1 just yet. GPS Analyst is only compatible with ESRI ArcGIS for Desktop software version 10 or earlier.
Trimble is currently working on a solution. As Trimble adds support for ArcGIS 10.1, GPS Analyst users that are still under a maintenance agreement will be able to convert at no additional cost.
It is recommended that if you are using a workflow that includes Trimble GPS Correct extension for ESRI ArcPad and GPS Analyst extension for ESRI ArgGIS, that you continue to ESRI ArcMap version 10 at this time. More information coming soon.