I love StackOverflow. From the first day StackOverflow was announced, I wanted to be a part of it. I knew that it would be successful and useful to at least a small group of programmers.
StackOverflow Careers? Not much. Why do they have to defend this careers thing so much? SO Careers is addressing a real problem, but I don't know if it is the right solution.
I don't mind paying, (paying back the great SO team is fulfilling) but the viability of the SO Careers model for an international audience is debatable. As EugeneG pointed out, we are not participating in SO just for the karma factor.