Dev on the Careers team here. I definitely agree with you about the shortcomings of other job boards for programmers - in many ways, that's why we're doing what we're doing.
Yes, we do actively recruit employers for Careers. The two major geographic regions that we've targeted so far are the US and the UK, and we have a significant presence in France and Germany. As you can imagine, we've got a number of other locations on our road map that we're working to expand into.
That being said, in terms of what you can do to help us: spread the word. The employers on Careers are very responsive to the fact that we have some of the best developers in the world as part of the SO community, but there isn't quite the jump from SO into Careers or vice-versa yet. As I mentioned, we do plan on expanding into other regions, but running parallel to that, if employers hear about devs talking about Careers, they will want to come to Careers too.
Personally, getting the developer community more actively involved in Careers is something that I'm very interested in. I'd like to see more ways on the platform to help you help us.