This is a big deal. If you use a browser on Windows that does NOT counter this, such as Internet Explorer, then you ARE vulnerable. I imagine Microsoft will come out with a special-purpose patch, but still, this is a pretty nasty issue.
Untrustworthy CAs have been a problem for a long time; we need mechanisms to address them. The terrible cert revocation system makes it even worse; you can't be sure that the certs are checked in many cases. Chrome's CRLSets are not the answer; they are not even the beginning of an answer. We need to fix the whole revocation system. Sadly, there hasn't been enough work or enough urgency on these problems; maybe this will light a fire under those efforts. I doubt it, but it's worth hoping.