According to TmoNews, the T-Mobile myTouch 3G should be starting to get an official build of Android 2.2 (Froyo) beginning as early as tomorrow.

This means all the benefits that come with Froyo will be available on these handsets, including the JIT compiler (for better performance), Exchange and security updates, Google Apps updates, Market updates, and more. It is unknown if this update will bring UMA WiFi calling.

Unfortunately, not all myTouch 3G’s are covered in this update. This particular update is reported to only update the first myTouch 3G phone: the Fender Edition. myTouch 3G Slide and refreshed 3.5mm myTouch will still need to wait for their update, which shouldn’t be too far after this release.

This will be a staggered roll-out expected to start October 13th, 2010, and run through the 25th.

(Source: TmoNews)