Presentation casting is also a potential game changer for Chromecast. I work in an academic environment and we are forever struggling with accommodating presentation interfaces - HDMI/DVI/VGA/Thuderbolt/etc ad nauseum.

The thought that a presenter could discover a Chromecast receiver and make a presentation directly to a connected projector via a Chrome browser tab could save us many kilo$ in hardware and support.

This might be even more powerful if the reciever can be implimented in software: https://github.com/dz0ny/leapcast