There isn't enough in this article to give one a sense of what portion of the lawsuit is bullshit. But it's safe to say that this should be a fun thing to watch as it develops. Hell even if the whole thing is baseless, I'd still buy the novel.
Update: Perdigao's suit is broken down by the law-talking people here (Part 1) (Part 2) (Part 3)
Link via Head Pelican
Update: There's now a Part 4 on folo. Also Wintermute's comments here are definitely worth a look.