Can Stack Overflow reputation be used as a benchmark in one's resume / during a job interview?

Yes, Stack Overflow can be potentially used a one of the important indicators of his/her abilities to do well in a technically challenging environment. I feel it gives a lot of insight into the candidate's technical inclination and interests. It shows that the person is proactive and updated in his/her area of expertise. It also to a certain extent indicates the person's ability to analyze and debug the complex problems. Since most of the problems posted have limited information about the system, so arriving at a "accepted" solution indicates excellent analytical abilities and experience in dealing with similar systems. But at the end of the day like all other things on your resume, it is your responsibility to sell your qualities and make them look useful for the interviewer and his organization.