T-Mobile planned to release the Samsung Galaxy S Android 2.2 update on Wednesday , but that day has passed and it hasn't appeared. The update is already significantly later than other networks, due to T-Mobile trying to offer the update over-the-air. 

T-Mobile have since announced on their discussion site that "Unfortunately the 2.2 update will not be available via KIES today as expected and Samsung have confirmed that FOTA will not feature as part of this update, but should appear at a later date. Samsung are indicating the firmware will be made available at some point next week."

So it seems that the update has been delayed till next week and they won't be offering the update over-the-air after-all.

There are a lot of unhappy people on the T-Mobile site  , so we expect T-Mobile to move as swiftly as possible to rectify the problem.