Chromecast has always been great at what it does, but up until now it's done fairly little (such as sit on its arse in the US while we wait for it to launch in the UK). Compatible apps have been just trickling in, largely because Google has been hand-picking what devs even get to play with the affordable wonderstick. No more! Google's opened up the Chromecast to developers everywhere. Finally, it should start getting the apps it deserves.
Developers can go download the Chromecast SDK right now, but what it means for you is that awesome-but-previously-verboten applications like AllCast—which basically turns Chromecast mirroring into Android AirPlay—are no longer off the table.
Sure, the wonderful effects won't hit until developers have a little bit of time to whip things up, but many have already been champing at the bit for months. There's already an AllCast update in the works.