I remember after the 2004 election, someone listed all states by income per capita and it was amazing. It was like all of the blue states at the top and the red at the bottom. When sorted by education, it looked almost identical (no shocker really).

I don't know that email can lean one way or the other since it's so private, but I don't see what you mean about blogs or social nets. I see no reason why they wouldn't stay lefty. They'll probably all lean in the same direction as the net on the whole.

The initial audience for sites like reddit and digg was for people who liked learning new stuff. Not any particular thing in general, they just liked the new and the unexpected. I think this runs counter to conservative nature. Conservatives like learning but they like learning about what they already know about.

Talk radio is the bastion of conservatism because you know what to expect. Comedy, on the other hand, thrives on unpredictability and the ability to shock. I don't think it's a co-incidence that poltics falls so neatly across these dividing lines.

My prediction is that email, social networks and blogs will all be conservative leaning medium. It hasn't seemed to have happened for social networks, mainly because of Obama's heavy use of them compared to McCain and because the demographics are still slanted towards liberalism. I don't know why blogs lean liberal, maybe due to the presence of commenting systems as a tipping factor?