As mentioned at Google I/O android devices will have the ability to mirror straight to Chromecast. Users of Google L preview already had a chance to try it out but now Google has sent out an update so other devices running 4.4 and above can mirror their devices to their Chromecast. If you own a Nexus 5, Nexus 4, Nexus 10, Nexus 7 2013, Note 3, S4, S4 GPE, S5, Note 10, HTC M7, M7 GPE, LG G2, and LG G3 you should be able to try it out when the Chromecast is updated to 1.7.7. Those with a Nexus 5 and Nexus 7 2013 should be able to try it now without the Chromecast app. Be patient if it does not work right away your Chromecast will need to update as well in order for it to work. The first time I tried it could not find my device. After my Chromecast rebooted and updated itself it worked. Be mindful this is still in beta mode so it will probably fail/disconnect after a minute or so.