To me this is a killer feature that would get me to buy an Apple TV...

If:
- the content providers allow it, and
- it actually works well and looks good

Has anyone been using this? If so, how well does it work and what video apps are allowing it? (Hulu, ABC, BBC, Crackle, etc)

Even if the wireless mirroring doesn't look good, the HDMI option wouldn't be a big compromise.