I'd been assuring people that the Chromecast would become even more useful soon and I was right. Google just announced that it's added 10 new apps, actually more like directly supported media services to Chromecast.
These are: VEVO, a self-proclaimed MTV for the Internet age; Red Bull.TV sports; Songza, an Internet music station; PostTV, the Washington Post's Internet TV channel; Viki, international TV shows and movies, primarily from Korea; Revision 3, techie TV shows; and BeyondPod, a popular podcast manager.
Plex is the most well-known of these media servers. Plex, a fork of the open-source XMBC can run on Linux, Mac OS X, and Windows. With it you can stream video in a variety of formats from local drives, network drives, and some cloud services.
You can, of course, continue to play many video files simply by opening their files from your Chrome Web browser.
Google didn't mention it this time, but it's also become clear that screen casting will be coming to Android soon. In the recent Android 4.4.1 update, there were hints in the code that the ability to "cast" an Android display to a Chromecast-equipped TV was on its way. This was further confirmed in the latest Android 4.4.2 where "Cast screen" is an option under the Display settings. Unfortunately, in my tests, this still isn't working. My 2013 Nexus 7 with Android 4.4.2 was unable to detect my Chromecast.
Still, it's only a matter of time before the newest Android tablets and smartphones will be able to share their displays to Chrome cast-equipped HDTVs.