i wouldnt recommend in case you dont understand the repercussions, main one being once rooted and the stock apps tinkered with you would be unable to install OTA updates. unless you reinstall the stock firmware and "un"root which still may be fraught with risk. additionally, you would void your warranty in case you root. and personally i dont think there is much to be gained from rooting the dhd.
p.s.: i have a Nokia N900 which i rooted the first week i got it, as it was simple and the phone/OS/firmware built for it. i havent done it on te DHD yet and dont intend to for the near foreseeable future.