It looks like the internet is a-wash with news that Mozilla will actually release Firefox 15.0 today. Right now you can grab the binary from a number of download sites, like:
The main place to get it though is the Mozilla FTP server. Here is the link to EN GB, which is what I installed:
Mozilla’s main page still shows 14.0.1 as the latest though.. perhaps it’s too early in the day for the US based organisation?
And description/discussion is available from places like GHacks:
and World of Free: