Wikipedia is requiring users to register before creating articles, after John Seigenthaler complained about a malicious entry on him. Problem solved? Probably not. Anyone can edit information in or out of articles with no accountability.
An interesting side story is the case of Adam Curry (yes, the former MTV veejay [veejay is one of the stupidest words ever]). He had a role in inventing podcasts, and he is accused of editing the podcasting entry at Wikipedia to inflate his role in the endeavor and delete references to others' work. Curry has apologized, blaming technology and ignorance. But the case helped put Wikipedia's credibility in the crosshairs even before the Seigenthaler problem. (And writing or editing articles about yourself on Wikipedia? Bad form there, just like it would be in newspapers.)
Today, New York Times business editor Larry Ingrassia sent a memo to reporters (later published on Romenesko) saying the paper has received a number of complaints about inaccurate information on Wikipedia. "We shouldn't be using it to check any information that goes into the newspaper," he said. I'd hope NYT reporters would know better. Most of the people who read A Capital Idea and Testy Copy Editors certainly do. (And I'll reiterate here: I love Wikipedia for exploring topics and learning new facts. But it's just a starting point; everything must be confirmed from a reputable source before appearing in a newspaper.)
Cnet has an article on whether Wikipedia is safe from libel liability.
As angry as Seigenthaler was, and as untrue as the article had been, it's unlikely that he has a good court case against Wikipedia, according to legal experts interviewed by CNET News.com. Seigenthaler himself acknowledged as much in a USA Today op-ed piece.But, as has also been discussed round here before, legal liability may mean nothing if your credibility is shot. No one will be reading you anyway.