Of course, it's unofficial. Folks at XDA Developers, your usual place for custom ROMs, didn't waste much time and got the HTC Sense 3.0 working on an HTC Desire HD and even though there are some issues, you can already get the novel lockscreen functionality and the rest of the latest Sense flare coming to your good ol' HTC device.
The ROM called RCMixHD Pyramid is based on a leaked HTC Sensation with Android 2.3.3 Gingerbread and requires a full wipe. The list of known bugs includes some problems with the Camera, Friendstream widget and SRS sound effects, but hopefully these will be fixed soon. Hit the source below for a download link and all the details, and don't forget to share how the flashing went in the comments below!
source: XDA Developers