I'm trying to put together all of the opinions, one way or another, that comprise the blogosphere... check out, for instance, Peak Oil Debunked and Peak Oil Optimist... the most cogent criticism so far seems to be coming from Jim Jarrell's criticisms of the Matthew Simmons book... the Wikipedia page on "Hubbert Peak" has a list of blogs too, tho' most of them are by the Peak Oil advocates... more on this later...