After making a splash by implying that Bush was part of a conspiracy:

In an excerpt from his forthcoming book, released Monday on the publisher’s web site, McClellan recounts the 2003 news conference in which he told reporters that aides Karl Rove and I. Lewis “Scooter” Libby were “not involved” in the leak involving operative Valerie Plame.
“There was one problem. It was not true,” McClellan writes, according to a brief excerpt released Monday. “I had unknowingly passed along false information. And five of the highest-ranking officials in the administration were involved in my doing so: Rove, Libby, the vice president, the president’s chief of staff and the president himself.”

McClellan’s publisher sets the record straight:

Former White House spokesman Scott McClellan does not believe President Bush lied to him about the role of White House aides I. Lewis Scooter Libby or Karl Rove in the leak of CIA operative Valerie Plame’s identity, according to McClellan’s publisher.
Peter Osnos, the founder and editor-in-chief of Public Affairs Books, which is publishing McClellan’s book in April, tells NBC from his Connecticut home that McCLellan, “Did not intend to suggest Bush lied to him.”
Osnos says when McClellan went before the White House press corps in 2003 to publicly exonerate Libby and Rove, the problem was that his statement was not true. Osnos said the president told McClellan what “he thought to be the case.” But, he says, McClellan believes, “the president didn’t know it was not true.”