- If product is brand new - release often
- If product have maturity - 1 year - 2 years release cycle is for you
- If product is platform - at least 3 years.
Ok, the article is from 2002 (what? yep, that old). So there was no distributed version control system (no, really, first releases of Git or Mercurial were at April, 2005).
Now, how did it changed the world? It actually changed it pretty dramatically. Before the main workflow was to develop a set of big features and then go to "pre-release cycle", when you fix issues, add small features and get your QA cracking your software. Because of that if you have 1 year release cycle, you would have only 3-5 month to get big features to the system, and then you have this cycle of getting software to production form.
Behold, DVCS gave you an option to have master branch in "release" form all the time. If you are doing a work that requires more than one commit (which any normal work does - because you should commit frequently) you just put in separate branch, which will be merged when it's ready (and may be even tested by QA). When in old world you would just make you current state unreleasable by pushing your commit to trunk (ok, there was branches in SVN... but really, did somebody used them to make new features?).
Let's look at Github - they've made 2000+ releases at 6 month period. Some of them sure were pretty small - a bug fix, a simple button that million customers asked to add or just a tooltip that made better usability. But some of them were pretty big - new interface, or changing backend, or may be new system of distributed handling of repositories (I'm making this up, though). The idea is - each release were the same - somebody finished his work in separate branch and merged it to main (release) branch.
Another example is Google Chrome - I think it's the best update system in the world that is in this world. IT DOESN'T NEED ME TO DO ANYTHING (I'm looking at you Flash, Java, ...)! Yes, and I like it. And they managed over past 4 years I'm using it - no to change interface unexpectedly - so the argument of "too frequent releases will affect usability" doesn't sound if the development process is built with usability in mind.
As a conclusion I would say, that frequent releases are a good thing when update system is very good (web service or auto-update without person even noticing) and when your have very concreate plan of features that will be implemented and not break usability (features add functionality, not complexity of UI).