Mozilla has decided to increase the version number of the next major release of Firefox to 1.5 from 1.1. The move is intended to reflect the myriad changes that have been implemented in this major release. Firefox 1.5: "Deer Park" should be with us in September of this year, with a Firefox 1.4: Beta release in August. You can read the Firefox 2.0/3.0 Roadmap here.