This Friday, December 8th is the Community Testing Day for Firefox 15.0.9/126.96.36.199 along with Thunderbird 188.8.131.52/2.0b1. Also Firefox 184.108.40.206 RC1 is now on the nightlies directory. I noticed today my ‘about screen’ no longer shows as Bon Echo 220.127.116.11 Pre, just Bon Echo 18.104.22.168
The estimated release date for Firefox 22.214.171.124/126.96.36.199 (this may also include Thunderbird 188.8.131.52/2.0b1 builds as well) is Thursday, December 14th. Keep in mind this date is not set in stone and could likely change depending on the outcome of Friday’s testing day.
News Source: mozillaZine Forums Firefox Builds