The Technology and Marketing Blog has an interesting analysis of the Barrett vs. Rosenthal case handed down by the California Supreme Court on November 20, 2006.  In its ruling, the court decided whether "distributors" of content have immunity under 47 USC 230 for Internet publications.

A major point in the analysis: 

No one is liable for other people’s content online–period (except for claims not covered under the statute–IP, federal criminal law, ECPA).

The author, Eric Goldman, points out that "active involvement in the creation of a defamatory Internet posting would expose a defendant to liability as an original source."  But in the Rosenthal case the defendant forwarded content without modification.  Accordingly, (at least in California) Plaintiffs that claim they were defamed in Internet postings may only seek recovery from the original source of the statement.

The Rosenthal case appears to protect bloggers who link to articles or republish content without modification but another case in the District of Columbia threatens to go in a different direction.  In general though it is still a good idea for bloggers to check out the accuracy of posts before linking or republishing content.