I have been using 3 HTC devices from year 2009, based on experience I can say that HTC has only survived due to the developer love shown over here at XDA, unless there was such a wonderfull romming community for all HTC devices they won't have existed, at least I won't have continued.
But Tegra/NVidia fault or not, I'm least bothered, when HTC sold a costly HOX to me 2+ years ago, they have touted it to be the best phone, if they cannot provide a update to it 2 yrs down the line, I guess the last update happened 1 year ago, I will be forced to buy a new device to stay updated. I have real feeling that this is a marketing strategy of HTC, they will be saying the same thing next year about M7 and the next about M8
I'm done with this .. will keep using the HOX, till I can.. then will ditch HTC. Believe me, I have a few friends who bought HTC devices after looking at mine over the years, yes minimum 20 / 30 devices. I will make sure they also stop buying... Good luck HTC.. I or my friends won't ever bother you in future.
Because of Qualcomm the s600 and s801 will be still supported a longer time so yea drivers will be there to get newer android versions running on it...so don't say it's HTC fault! There are many many other OEM which are much worse then htc ever was!