The two standards bodies trying to develop HTML 5 have agreed to split between 'Living' and 'Snapshot' builds.
The two working groups involved have run into troubles working together, and thus have decided on the split. To this author, this is a project fork. Sometimes, project forks kill a product, but other times a project fork can end up more successful in the long run. Take, for instance, Joomla, which was a fork of Mambo, and is now one of the most popular content management systems for small to midsized websites. However, WordPress and Drupal have not forked, due to strong development heads at the forefront of the projects, and are also very successful in the same arena as Joomla.
However, project forks can lead to competing products. LibreOffice forked off of OpenOffice due to a similar style dispute going on with HTML 5, leaving users confused on which version to turn to in order to do their word processing and database work.
HTML 5 has shown promise in eliminating the need for Flash on devices. Apple especially is banking on HTML 5 replacing Flash, due to their dispute with Adobe. With two versions, however, how far they diverge from one another and force browser manufacturers to adapt between the two standards will make or break this decision.
For more information, check out the article at http://techcrunch.com/2012/07/22/html5-work-splits-into-living-and-snapshot-standards-developers-need-not-standard