A couple of days ago biblatex v0.9 appeared on CTAN. As usual, there is a long list of changes, bug fixes and so on. The restrictions on inclusion in TeX distributions have been lifted, and so it’s already available in TeX Live. At the same time, biblatex-biber has been uploaded to CTAN, so hopefully ready to use versions will be added to the distributions at some point (MikTeX is likely to be first, I suspect).
I’ve just uploaded an updated version of biblatex-chem to CTAN, to keep in sync with the changes in biblatex. I’ll try to get biblatex-nature and biblatex-science done in soon (today) so that everything is working.