On the heels of the release of the Windows Mobile 6.1 Professional upgrade for the Sprint HTC Touch came (and went) the upgrade for the Sprint HTC Mogul. Much like the HTC Touch upgrade, it promised other enhancements including Sprint TV and all enhancements included in previous software upgrades (including EV-DO Rev. A functionality, enhanced GPS functionality and a Task Manager on the Today screen).
It’s not clear why the upgrade was later removed although WMExperts suggest that it could be available again on Monday. Keep that link handy if you missed the upgrade the first time round.