There's only two things we can say with certainty about Telstra's "official" Froyo update for the HTC Desire: it's already overdue, and no one at Telstra seems to know yet when and how it will be delivered.
As we reported yesterday, Telstra missed its own self-imposed one-month deadline for the update and then announced via Twitter that the update was too large for an over-the-air update. But then the plot thickened again, with a Telstra media manager tweeting that a final decision on whether the update would be delivered over-the-air wouldn't come until closer to release time. And nobody wants to say when release time will be, presumably from having been burned on the topic several times before.
At this stage, ignoring the official channels and going with CyanogenMod is looking better than ever.