Rooted my Desire HD 3-4 weeks after I got it. Did it to remove bloatware and, ya know, because I could!!
The phone is rooted and S-Off, running IceColdSandwich (and ICS custom ROM)... just not had the time to try JB on the phone... others in the DHD section have though, so I know the hardware is capable, even though HTC won't release it. Their excuse
reason is that, to run JB on the phone, it would require a repartition of the system (or something like that), which would result in the loss of user data. They've even said that, for advanced users and rooters, this is understandable/acceptable but that the majority of "normal" users wouldn't be happy. Guess I understand their reasoning, but why not release the source code, so that ROM devs can work their magic and we could have JB on our devices without the bugs?
Recently ran an RUU to update to the most recent radios (simpler to do that and re-root by flashing a recovery as an update in HBOOT)... stuck with Stock unbranded HTC for less than a day, before heading back to IceCold! Guess I just don't like Sense