This blog is updated daily.
A general description is here.
There are new font families for the 2014-5 URW 2.0 fonts - see ‘?pdf’ - which are included in recent versions of ‘ghostscript’. These have font widths for Greek glyphs and a few others which were missing from the original versions (whose font families remain available for reproducibility).
The included BLAS sources have been updated to those shipped with LAPACK version 3.12.0. The changes are almost entirely cosmetic.