Microsoft Windows Kill Switch?

I came across this article over on Bruce Schiener's blog. Apparently Microsoft is refusing to respond to reporters valid questions about WGA and the possibility that they may be able to disable your system sometime in the near future.

As we have mentioned previously, as the WGA Notifications program expands in the future, customers may be required to participate. [emphasis added] Microsoft is gathering feedback in select markets to learn how it can best meet its customers' needs and will keep customers informed of any changes to the program.