I’ve just released version 1.3 of siunitx to CTAN. Although the changes are not large in number, they are important. First, I’ve altered the default code for \micro (μ), as the previous version did not look great: an important change, hence the bump of version number. Second, the packaging has been altered to make life easier all round. You can now extract the package and typeset in one go from the .dtx file using LaTeX, or just extract it using TeX. Overall, the effect is much cleaner than the old version. Of course, there are some bug fixes too.