XBMC 13.0 "Gotham"
was just released at the beginning of the month but already the XBMC 13.1 point release is up to its second beta.
The forthcoming XBMC 13.1 update is focused on addressing fallout from the 13.0 release with many bug-fixes and is not intended to present any new features. These current beta releases should already be safe to run in place of XBMC 13.0.
Among the bug-fixes addressed in the first two betas of XBMC 13.1 Gotham include better recovery of NVIDIA's VDPAU on errors, other VDPAU fixes, fixes for minor memory leaking, FFmpeg / FLAC fixes, broken M4A / MP4 playback, and other changes.
XBMC users interested in the very latest 13.1 Gotham changes can find out more from the 13.1 Beta 2
announcement that came on Sunday.