Scotticus made an observation recently on his webpage, and since he doesn't allow comments I'm commenting here:
A recent Pew Research Center study shows that people who watch The Colbert Report and The Daily Show correctly answered 54% of questions about current affairs, whereas viewers of regular TV news correctly answered only 35%. I'm not sure what to make of that finding.
This is a classical example of statistical confounding. While I value the real-news perspective of these programs, watching them probably has no effect on current events knowledge. The Daily Show is a comedy program aimed at well-educated, mainly liberal young people with an interest in current affairs. TV news programs are aimed at the typical local viewer. It's very likely the existing differences in the audiences accounts for the difference in news-awareness.