ARS Technica reports Mozilla will switch to a 16-week development cycle for Firefox after the launch of Firefox 4. This means we can expect three more major releases this year.
As we discussed in our coverage of the roadmap, Mozilla's plan is ambitious and will require a dramatic overhaul of the Firefox development process. Mozilla—which has historically had lengthy development cycles and protracted beta testing—will have to transition to a faster and less-conservative approach to release management. The organization has authored a document that describes how such a transition could potentially be achieved.
The document describes a 16-week development cycle in which software improvements will flow down through several tiers. The tiered model appears very similar to Chrome's channel system. New code will initially land in mozilla-central, the repository that hosts the tip of the code base. As new features solidify, they will roll through "experimental" and "beta" channels before arriving in a stable release.