Normally I would agree with this but look at the Galaxy series phones. EVERYONE is pissed about the updates not coming out on them that were promised months ago but the complaints haven't really sped anything up.
Apples and oranges.
The Evo was the first non-Google phone (Nexus One) to get Froyo - it leaked by end of July and was fully out August 3, 2010 - so, that's not Sprint's doings - it's Samsung's.
HTC has the best upgrading record as of last year in the business.
Remember that the Gingerbread source code made it into the AOSP repository on or around December 18, 2010 - add in a little holiday time alone and we're barely 6 weeks out from that.
Add in the CES activities plus the launch of the Thunderbolt and a few others - we're not so far behind at all with either the Shift or the Evo. (My original projection for an official Evo update to 2.3 was by today, btw - and that would have been _soonest possible_.)
I'm personally still noodling on a new expected date - but summer or so is way too far out there.
The rumor mills have yet to decide what the real deal is with 2.4 (the article that launched that one was still calling it Ice Cream instead of Ice Cream Sandwich) and Honeycomb as tablet-only, despite the SDK showing otherwise.
I'll take this initial shot - within 30 days, we'll have 2.3 and the new Sense --- unless there's something fundamentally defective in 2.3 and that's the real reason to push out to 2.4.