Re: I on't think this is a good idea.
It just appeases the development community and provides them top notch hardware with stock Android where Nexus hardware is good, but never as good as Samsung or HTC flagships. So in this case, they get to have it both ways. But I don't see it as a loss for HTC, it's not like this messes up sales of the ones that comes with Sense, it just gives those that prefer vanilla Android the ability to choose a phone with top hardware without having to void their warranty by unlocking and flashing a custom ROM which is what happens on the carrier version.
It also gives HTC a chance to pick up the next Nexus device as well. Of course they wouldn't be looking to make a super phone for a nexus but they could make a device so google can price it where they want and sell 1-2 million of them. So I see it as a good opportunity for them and not affecting sales of the current One.
Having said that, I agree with the part that those Sense features are what I like most about the phone so I wouldn't buy it if I had to spend $600 and had to choose.