But does it do...
"The Chromecast does not at all work in the way you describe, The WiFi does not "suck video out of devices running a chrome browser" in fact to use the Chromecast in the way you describe, requires the computer to do realtime audio, video encoding of the chrome tab that is being cast, it then serves this video stream to the Chromecast over HTTP. Because of the requirements this places on the computer - the experience is generally not wonderful, and is a last resort to provide a way to get the content to the TV. The Chromecast in fact sits on top of the DIAL protocol, and opens a websocket to connected sending apps (receiving apps are basically webpages that are downloaded on-the-fly from the internet, via HTTPS when they are launched)."
Except when it does, you know, if you drag and drop a video into the browser window and cast that tab, or just cast a tab in general, whereupon it does realtime OnTheFly enconding and transfer of the tab contents - although I'll grant you, using it as a 'control' device to push content past the browser to the device natively is better in most cases (IE casting Youtube directly to it, Netflix etc).
TabCasting is handy if you want to show someone, say, an XKCD or TheOatmeal comic, though, rather than passing a laptop or phone around, just cast the tab to the telly in 720p quality - works nicely.
I've been using Videostream a lot recently, which is a natty Chrome extension that uses the decode grunt of your computer to push pretty much anything your computer can draw, to the Chromecast dongle - so FLV, AVI, WMV, etc, all play on the telly. I've yet to find anything it won't transcode and fling to the telly without any framedrops at all.
If you have a lot of legacy rips in non-de-jour formats (WebM/H264) then it's an utter godsend.