Since the launch of WordPress 3.0, the WordPress team has been slowly adding improvements with each release. They haven't been a major overhauls.

On the other hand, the Drupal community is gearing up for a hugely ambitious rewrite of the platform with Drupal 8 next year.

Joomla is trying to find a middle ground between these two solutions, neither very incremental, nor very radical.

Here's an overview of the upcoming release cycle. If things go well, there should be good news all around: