Good as Sense is, I do think HTC uses this as an excuse too often. They seem to claim that it is tightly interwoven with the operating system itself, but I don't think it is quite as much as they claim.
We have a replacement home screen, a series of apps and widgets. It has a slightly different colour scheme, replacement keyboard and other things that Android happily lets you change (hence the third party apps that do much of what Sense does).
So, to me, Sense being modified to work with 2.1, 2.2 or whatever is a red herring. The problem is that everybody believes it and spreads the word and HTC does nothing to correct them (why would they?).
I'd love for someone (ideally from HTC) to come on and, even if it's anonymously, explain why Sense is so unique that it can delay - or even prevent - future OS updates.
I'd also like to ask the same question to Sony Ericsson for their similar excuse for delaying 2.1 on the X10. I hope to God that they're now going to skip to 2.2!!
In the future, given the range of third party apps (home screen, gallery, web browser, keyboard etc), I'd probably look to a manufacturer that keeps the phone as 'vanilla' as possible so we don't get stuck with old software because of the non-standard stuff. I wonder if Sense could actually be the undoing of HTC as and when loads of other manufacturers start making equally impressive Android devices (hardware/screen wise).
