Over the weekend, Justin from the Telstra Twitter team announced that the Froyo update for HTC Desire owners wasn't going to be an OTA update after all. Turns out, all that 2.2 goodness is just too big, so instead the OS update will be made available from HTC's website for download.
As to when it will be made available... well, it's already been a few days since the last tweet. Let's hope for any minute now...
UPDATE: The update now rests in Google's hands, according to this tweet from Telstra's Craig Middleton:
FroYo passed Telstra testing last week & is with Google for the final engineering OK. Release will follow in a few days. Thx 4 patience.