A fourth release candidate of GRASS 6.4.0 is now available.

Source code:
https://grass.osgeo.org/grass64/source/
https://grass.osgeo.org/grass64/source/grass-6.4.0RC4.tar.gz

To get the RC4 source code from SVN:
svn checkout https://svn.osgeo.org/grass/grass/tags/release_20090412_grass_6_4_0RC4

An announcement has been drafted at
https://trac.osgeo.org/grass/wiki/Release/6.4.0RC4-News
(all RC news will be merged into the final announcement later)

Key improvements of the GRASS 6.4.0 release include enhanced portability for MS-Windows (native support), hundreds of fixes, the new wxPython based portable graphical interface and much new functionality.

Release candidate management at
https://grass.osgeo.org/wiki/GRASS_6.4_Feature_Plan

We hope to get out binary packages over the next days.