Sense UI or some pre-installed apps would be cleared out to make room in the Gingerbread house, but now it seems the update is so unstable that HTC is only prepared to release it as a ROM via its developer site. That means a factory reset of your device, a bunch of worries about SMS and MMS not working properly, and a cold disclaimer in the event of things going wrong. Still, at least HTC gave (some of) us the choice. Visit the source link below for deliberately spooky instructions.
[Thanks to everybody who sent this in]