The World Wide Web Consortium (W3C), the group that manages development of the main specifications used by the Web, has proposed a new plan that would see the HTML 5 spec positioned as a Recommendation—which in W3C's lingo represents a complete, finished standard—by the end of 2014. The group plans a follow-up, HTML 5.1, for the end of 2016.
Under the new plan, the HTML Working Group will produce an HTML 5.0 Candidate Recommendation by the end of 2012 that includes only those features that are specified, stable, and implemented in real browsers. Anything controversial or unstable will be excluded from this specification. The group will also remove anything known to have interoperability problems between existing implementations. This Candidate Recommendation will form the basis of the 5.0 specification.
In tandem, a draft of HTML 5.1 will be developed. This will include everything from the HTML 5.0 Candidate Recommendation, plus all the unstable features that were excluded. In 2014, this will undergo a similar process. Anything unstable will be taken out, to produce the HTML 5.1 Candidate Recommendation, and an HTML 5.2 draft will emerge, with the unstable parts left in.