I'm not sure if this is an official channel, but found this on facebook (thru' another site)
facebook.com/pages/HTC-EVO-3D/134339929978564?id=134339929978564&_rdr HTC EVO 3D | Facebook
A very cryptic post "June 16..???" - not sure if that means that is when ICS will be released for sprint users
(June 16th is a Saturday - I thought most OTA updates were done on weekdays - no?)
Edit: Not sure why the link wasn't showing up in the post (it does show up in edit mode) -
I just took a look at that facebook page, and I'm pretty sure it's not an official HTC operated page. It looks like a fan page. So that doesn't seem to confirm that June 16th is a real date, only that others have heard the same rumor.