I, for one, welcome the fast release cycle. To me the version number isn't important, new features are.

Look at how long it previously took Mozilla to get major releases (and major features) out the door: http://en.wikipedia.org/wiki/History_of_Firefox#Release_hist...

The web evolves at a rapid pace. Now that browser vendors are implementing new features at a faster rate, developers can deliver better experiences to end users with a greater degree of certainty that each will have the same experience the developer intended.