The Mozilla Foundation has decided to make the next version of Mozilla Firefox numbered 1.5 instead of the previously planned 1.1. Asa Dotzler explained that the number change was due to the sheer volume of changes in the Firefox core (Gecko), and a .1 increment might mislead the public into thinking the update was relatively minor.

This does not mean that the date of the next major release has been changed. The only thing that has changed is the version number that will be given to this next release. Obviously, the previously scheduled 1.5 release (codenamed The Ocho) will end up being released with a different version number, currently planned to be 2.0.