Several MobileTracker readers that use the HipTop (AKA T-Mobile Sidekick) emailed to let us know that the OS has been updated to version 2.3. The update includes JavaScript support, a feature of upcoming special edition black Sidekick II that we highlighted yesterday.
The changelist has the full details.
Like other updates for the HipTop, they are sent over-the-air (OTA) to each device. It's up to each operator to push the update.