[Silhouette]

Right there, in the very first sentence of the article we're discussing, there's a reference to the channel switcher, which was pulled at the last minute from Firefox 5 having been in the dev builds for a while.

Moreover, as I mentioned before, the software world is full of examples of this on all scales. Windows Vista lost most of its headline features before it finally shipped, after months of building up expectations by Microsoft. No project is magically immune to this possibility.

Your claim about the certainty of shipping something because a test version was integrated into a dev build is simply wrong, and that is why I use terms like "vapourware" and why I think this sort of discussion is premature for HN.

Anyway, enough of the meta.