I posted about what I found works and doesn't work in a previous thread:
Works OK for me but it's a bit picky. I'm finding that per the instructions I do need to first power off the monitor before connecting the EVO. Still images only work in slideshow mode but the slideshow controls are visible on the EVO while the slideshow is running on the monitor. So you can pause, go forward and go back. Videos work fine from the gallery app, YouTube app, and TV.com app. SprintTV did not work though (not a fan of that app anyway).