The coverage of the McLellan tell-all book has focused on the White House spin, which amid all the bluster about surprise and how this isn't the Scott they all knew (come on, why should voters care that you're surprised), they aren't really contesting the assertions, or if they are, they're doing it weakly.
Probably some of them want to have jobs in the future, and lying right now wouldn't help them in the careers. Further I think almost everyone who has been paying attention knows that what McClellan says is true. Why didn't he speak out earlier? Why didn't a lot of people? Also consider the possibility that other people in the White House got scooped, the ones trashing McClellan and are jealous that his tell-all book got out before theirs, and others are likely to be tried and perhaps go to jail for their actions. In other words, they all have axes to grind here.
The other point being overlooked, and this is a real problem, is that he says that the press was complicit. This is the more important allegation, and unsurprisingly, it's being swept aside by the press. Had they done their job, and pressed for the truth, it would have been easier for insiders to tell them the truth. But corporate-owned media isn't interested in helping us make decisions as a country, they're only interested in ad revenue. That's why it's so important that we're creating new media that isn't so conflicted, and why the question of whether bloggers run ads or not is far from a trivial issue.
In court, if you have a conflict of interest, you're supposed to disclose it, and if it's serious enough, it disqualifies you. I've recommended many times that professional news media should have relationships with less conflicted bloggers for circumstances like this, so when they become the story, the public can have a discussion about them using the channels they own. They don't have much of a choice here, because the channels are going to develop with them or without them. We could all save a bunch of time if they didn't fight it, and welcomed amateurs into their midst.