Joomla Magazine recently shared their CMS Development Strategy.
Since the release of Joomla 1.6, back in January 2011, Joomla started to use a new development strategy. The development strategy is explained in a long article on http://developer.joomla.org/strategy.html, not always understandable for the international Joomla Community. The actual development status including release and End of Life dates is listed on http://developer.joomla.org/development-status.html
Here is a lovely Infographics to sum it up: