Mozilla, the makers of the Firefox web browser, want to release four versions per year. I find it funny that most of the discussion about this in the arstechnica comments is about what the version numbers should be. As if this is the most important aspect of the decision.
Software development revolves around releases. A release is a software version that is available for purchase or download (ie: released to the public). Software manufacturers will then add new features to this old software and release a new version later. A software version number tells you which release of the software you are using.
By convention, the first release is called 1.0. The next major release is called 2.0. If there's been only bug fixes the version would be something like 1.0.1. If they're fixing bugs and introducing a few minor features the release might be 1.1. If they're introducing lots of minor features they might skip a few numbers and go straight to 1.5. The result of all this is you can use the version number to make an educated guess as to how much has changed in the new version.
All this version numbering is based on the assumption that you actually have major releases and minor releases. Some software is developed continuously and released on a fixed schedule. Every four months or so there might be a new release which contains whatever is finished at the time. Some releases might have only have bug fixes but others may have major new features. If you try and fit this into a typical version number scheme it becomes difficult to decide which release get a new major version number and which require a minor version number change.
Google's chrome Web browser is a good example of software development on a schedule. They have effectively abandoned major and minor version numbers. Google increments the major version number by one for (almost) every release irrespective of what new stuff it contains. We used a similar approach when we were developing Myster. Releasing on a schedule is a natural fit for the development team but can confuse those who expect a more traditional numbering scheme. It's confusing because the version number seems to lie; there's not always major new features despite the major version number change!
Mozilla has said they will be putting Firefox on a scheduled release system with four releases per year. Up until now Firefox has been using the more traditional release schedule and version numbering scheme. The new release schedule basically mandates that the major version number is incremented by one. Simply increasing the major version number by one with each release is so much easier than having quarterly arguments as to what the version number should be based on what happens to be in that particular release.
In these days of automatic updates, version numbers are practically irrelevant. What matters is whether you're up to date or not. I would like Mozilla to downplay Firefox's version number if they are releasing on a schedule. If they focus the conversation on the capabilities of the software and less on what it's version number is most other concerns will fall into the background as people adapt to the new reality.
Me from the present says: I'm using Firefox 9 and feelin' fine.