The Virtuous Team has just released a custom ROM for the HTC EVO 3D based on a leaked version of the upcoming ICS update. This includes Android 4.0.3 and Sense 3.6; interestingly enough, this particular ROM is based off a leaked RUU for Virgin Mobile's version of the EVO 3D, which has yet to be released or even officially announced.
Right now, some people are experiencing problems with this ROM booting up, or issues with bootlooping. Additionally, a few people have accidentally updated their hboot versions, which in turn locked their devices. However, this can be easily circumvented by deleting the hboot that was included in the leaked RUU.
Active development on this ROM is currently underway to make sure everything is working properly, and it is only a matter of time before we see a fully functioning release. If you're brave enough to dive in head first, you can download the ROM at the link below, or simply follow that thread for the latest updates.
[RootzWiki] Thanks, Erin and Tony!