This Friday, December 8th is the Community Testing Day for Firefox 15.0.9/18.104.22.168 along with Thunderbird 22.214.171.124/2.0b1. Also Firefox 126.96.36.199 RC1 is now on the nightlies directory. I noticed today my ‘about screen’ no longer shows as Bon Echo 188.8.131.52 Pre, just Bon Echo 184.108.40.206
The estimated release date for Firefox 220.127.116.11/18.104.22.168 (this may also include Thunderbird 22.214.171.124/2.0b1 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