OK. There are two things to say about Karl Barth which (I think) are somewhat important:
 Karl Barth lived in one of the most intellectually-challenging ages of all human history, and he lived in what has to be the epicenter of the "chaos", for lack of a better word. Living as we do today, in the aftermath of that age of intellectual calamity -- that is, the age between 1900 and the end of the second World War -- we take it for granted that it's somewhat simple to identify "liberalism" and "conservatism" and "the Gospel" and "heresy". However, if you were born in an age where nothing was that certain, and all things relating to the Christian faith were frankly in question historically, sociologically, escatologically and politically, you might turn out like Karl Barth if you loved Jesus enough.
There's no question: Francis Schaeffer and Cornelius Van Til both thought Barth was a problem (and they're not the only ones). But we have to ask if Barth wasn't actually the solution which bridged the gap between rank German liberalism and reform to a better way.
 In that, however, is Barth a station on the historical subway line, or is he the place where everyone ought to get off the train -- a terminal? It seems to me to be extraordinarily shallow to read Barth and then say, "oh boy: that's where we have to buy 40 square and settle down." Van Til called Barth "poison" -- that's not just some guy with a blog and his two buddies declaring who is and isn't a heretic. Barth clears some of the ground that the German liberalism of his day had covered with a briar patch -- but he's hardly the end point. We ought to read Barth and understand what he was talking about and against, but we can't imagine that he's the tonic for all ills in all ages. I think Van Til's criticism that Barth is inherently synergistic (that wasn't VT's word, but that's the word the blogosphere uses to mean what he meant) is very perceptive. It's a first generation against pure 20th century humanism, but it's a half-breed generation still harboring the idea that man has some peer-like relationship to God.
So as some quarters of the blogosphere gush over Barth and give Zwingli and Calvin low grades because they don't write in a style which keeps one on the edge of one's seat, let's try to keep things in perspective. Let's not over-react against their fan-like cheering of Barth, but let's also not make Barth into some kind of pure antichrist when the problem is not what he said, but how some people are willing to use (or abuse) what he said.