There is an update notification coming Monday. Make sure you have the "Scheduled check" box checked in the Menu>Settings>System Updates>HTC software update>Scheduled check. I would try that. If it doesn't update, contact Sprint Customer Service.
In another forum, a member (Brewz), said he removed his battery for about 5 minutes. When he replaced it and his phone booted, he was able to update without any problem. Try it.
I was able to get the update this morning (6/21), tested some of the issues that others have had, but all is good so far (ring tones Exchange etc.). Only issue (if you want to call it that) was imputing my id and pw for gmail. to sync the first time.