Yesterday the first beta of the next XBMC version Dharma was released. The biggest new feature there is the Add-ons system. Now all functionality that doesn’t belong the core of XBMC will be an addon. As result, it’ll be much easier extend base functionality.
Dharma Beta1 builds are available now for all OS. Just visit the download page to get desire one. But be very careful with upgrade existing system. Backup everything you need and be ready to submit new bugs.