It's not often I mention or link to Media Matters, but this piece is kinda interesting, if a bit self-serving for lefties, about whether Fox and MSNBC are truly opposites on the partisan/ideological spectrum.
The column's point appears to be that MSNBC is nowhere near as overt in its partisan leanings as Fox. As a long-time viewer, journalism professor, and media scholar, I'd have to agree -- but nowhere do I see a careful, systematic content analysis of both cable networks to truly settle the issue. That said, I have noticed more and more of an anti-Obama, anti-Democrat theme appearing in Fox's "straight news." I expect that from Hannity, Beck, etc., but the straight news, such as it is on Fox, always struck me as just that. But of late, I've detected more and more hints of partisanship even there. For MSNBC, less so. Again, none of this is systematic, none of this sound methodologically, just my impressions from a lot of television news viewing with a trained journalistic, and researcher, eye.