Since then GetReligion and Parableman have had follow ups dealing with rebuttals from the athiest community. A common comment denying his "conversion" (more on that later) use words from Flew himself:
We negative atheists are bound to see the Big Bang cosmology as requiring a physical explanation; and that one which, in the nature of the case, may nevertheless be forever inaccessible to human beings. But believers may, equally reasonably, welcome the Big Bang cosmology as tending to confirm their prior belief that "in the beginning" the Universe was created by God.The problem is that flew wrote those words in 2001. This is not Flew denying his conversion. This is Flew writing on a similar topic over three years ago.
Flew's actual "conversion" is worthy of note. He is now a deist similar to Jefferson. He is not a Christian in any way shape or form. The main reason for this conversion was his inability to reconcile certain incredible improbabilities that are required for abiogenesis and cellular level evolution.
Abiogenesis (literally beginning without life) is the process where a batch of non-living chemicals become living cells capable of reproduction. Once you have a that cell, evolution can work on it to build complexity through known selection mechanisms. At least in theory it can. One of the early assumptions in evolution was that abiogenesis was simple, it is not.
Evolution has been called an analog theory for a digital medium. When you look at multi-celled life forms you can pretend that the steps are small and basically continuous. When you look at the cellular level, evolutionary increments have "zoomed in" and become leaps requiring multiple complex biochemical components interoperating simultaneously in order to function. The more we learn about cellular biochemistry the more we learn that it is complex and even small evolutionary steps are non-trivial. In some cases cellular systems don't seem to have intermediaries that still satisfy evolutionary requirements for net benefit to the lifeform. Systems with this problem can be termed "irreducably complex."
Michael Behe, a biochemist and intelligent design advocate, compared this to a mouse trap. If you take away any component, it doesn't catch mice. Even if you have similar components lying around (some type of spring, a few pieces of metal, a wood block, etc.) the likelihood that they could be assembled into a functioning mousetrap is low. So how do you build such a system through selection? The answer Flew and others have come to is that you can't, these systems are irreducably complex. Flew postulated that a higher being contributed to the assembly of the mousetrap either by reducing the improbabilities involved or by performing actual assembly.
I have read evolutionists attempts to solve this problem, but they usually amount to little more than sophistry and wishful thinking that still leaves large gaps. The first few chapters of Richard Dawkins'The Selfish Gene come to mind. Lots of hand waving, little hard data at present.
UPDATE: Matthew Yglesias is covering it and he has a few links to athiest bloggers if you want to read them. He also makes this very astute observation:
Its upshot is, for all intents and purposes, the same as the upshot of atheism. If I decided that Flew was right, I wouldn't start behaving differently in any way, or even need to modify my beliefs about any other subject.He is right of course, which is why the huge impact of this story is kind of funny.