Marek Olšák has made some bug fixes to the libtxc_dxtn library (a library for mesa to allow S3TC). First of all you can download the updated version from http://people.freedesktop.org/~cbrill/libtxc_dxtn/libtxc_dxtn-1.0.0.tar.gz
. Next to that the source code location changed (the code can be found at http://cgit.freedesktop.org/~mareko/libtxc_dxtn/
). Marek also replaced the build system of the library by autotools, but this is not released yet.
A recent discussion about if this library should be added to mesa shows that this is not a desired option. This is because it would require the end user to recmpile the whole mesa instead of this single package.