A while ago the XBMC 13.0 feature freeze has been anounced. This means no additional features will be added and you could be expecting to see XBMC Beta releases coming out. The XBMC 13.0 release is still scheduled for this year.
In the meantime some additional bugs have been fixed in the 12.x branch. This might indicate an additional 12.3 will be released as well in the future. Be sure to check out the xbmc.org website for the latest news.