Last week, a group of notoriously talented HTC EVO devs (Shinzul included) better known as teamwin showed off the progress they've been making with getting HDMI mirroring to work on AOSP-based ROMs.
Today, they've released an alpha version of what they're calling HDMwIn, an app that enables full HDMI on CyanogenMod 7 (CM7)—better known as the king of AOSP—Sense, and other ROMs. Unlike FullHDMI, the first mirroring app to be released for the EVO, HDMwIn will eventually be integrated into the CM7 tree so that it's included as a standard feature in all CM ROMs.
The alpha label should clue you in to the fact that this is still very much a work-in-progress, with sound not working on AOSP and an intentionally limited frame rate (for debugging purposes; future releases will be faster), but considering the collective talent working on this project, you know it won't be long before it gets better. In fact, Shinzul even says to "expect this to change rapidly."
The app is currently in flashable .zip form and includes a custom kernel that must be used for proper mirroring; other kernels will work but they will cause "awful screen tearing." Note that for GPL compliance, HDMwIn can currently only be downloaded by those who request an invitation, which you can do here.
Whether you choose to use teamwin's HDMwIN or orrebmas' FullHDMI, HDMI mirroring on your HTC EVO is definitely a big win.[HDMwIn alpha invitation | xda-developers] Thanks for the tip & pics, @JoshuaAlba!