Seems like the HTC phones are really taking up the lions share of Android news lately, doesn't it? First the G2 was rooted, and shortly after we learned that HTC did its best to prevent perma-rooting. And just this morning, we heard word that the Desire HD and Z are both being delayed. Quite a mouthful, we know - but now that you're up to speed: an enterprising individual by the name of kholk over at XDA-Devs has come up with a root method for the HTC Desire Z.
The method is very similar to the G2 method mentioned above - the process involves dropping a package on your SD Card and executing a few scripts.