Awww, that suxs! I'm hoping to replace my Desire Z within the next 3-4 months with another physical keyboard phone from them. Even if HTC reverse their decision down the track, it will take a good 6-7 months to bring out a good phone from scratch but that time I would have already got a replacement.
Anyhoo in saying that, I reckon that the least HTC can do for us is ask Qualcomm to release the camera source code to our talented developers here so they can develop custom ROMs with a full version of ICS. That should go a little way as a form of compensation for their crap business decision.