Microeconomics: Glenn Reynolds explains what it means for libel law when everyone is a potential pundit.
Update: Speaking of macroeconomics and the legacy media, Thomas Sowell notes a telling statistic:
During his long tenure as NBC News anchorman, Tom Brokaw took that program from last place among the big three broadcast networks to first place. But he had more viewers when he was in last place, more than 20 years ago, than he had in first place this year. That is because fewer people now watch NBC, ABC, or CBS News. Good!