We are not evenbalance, unfortunately - so nothing we can really do. They announced that they would not be supported Windows 7 until release.
As for supporting a beta OS, very few developers will do this for a piece of software that hooks into the system at such a low level. Windows 7 may yet undergo drastic kernel revisions, or have key APIs changed - that would immediately break new releases of Punkbuster. There is no cost effective way to support a beta OS with software like Punkbuster. So, they stick to supporting released and mainstream OS's until Windows 7 is in a state in which they can support it without fear of massive changes (which often happen in win betas) breaking their software at every turn.