Mesa 10.1.3 was announced this morning by Intel's Carl Worth and has a handful of bug-fixes over the recent 10.1.2 release. The Mesa 10.1.3 changes include an XA state tracker performance regression, a GLSL warning fix, and some other basic Mesa/i965 changes.
Those wishing to find out more about this latest stable Mesa 10.1 release can see the mailing list release announcement. The main reason for getting this release out already is due to the XA state tracker performance regression affecting the VMware virtual graphics driver with Mesa 10.1.2.
Meanwhile, when Mesa 10.2 ships shortly it's bringing many exciting new features but sadly is still coming up short of proper OpenGL 4.x compliance.