e10s Release Date
E10S is scheduled for Firefox 36 - February 17, 2015.
According to the Rapid Release Calendar Firefox 36 development begins Oct 13,2014. This is the version of the browser where Firefox's multi-process architecture will be moved from channel to channel (Nightly > Aurora > Beta > Stable) so that it is released to the stable channel of the browser on February 17, 2015. (Source =?, I read it on Ghacks)
e10s - How to testYou can test e10s in its own window, like Private Browsing, using the
Nightly channel's "File > New e10s Window" menu item. (Source https://groups.google.com/forum/#!topic/mozilla.dev.platform/q0Ku_8j26Pc )