I was really excited about the Chromecast when it was first announced. But sadly Google have really hamstrung it every step of the way.
Luckily, Mozilla is developing a very similar device (Matchstick [1]), and looking to do it better. I am unable to find the link at the moment, but they already support like 3 or 4 times as many media formats as chromecast. And Mozilla has a pretty good track record with hackable, open projects.