Hmmmm...
I don't think anyone has ever switchd from creo to evo. I know Mike the Wiz has become less 'hardline' creationist. Phatboy and mesenjah have also seemed to loosen up their stance a bit.
One of the few conversions I witnesed on this site was a mormon fellow who gave up on mormanisim in the face of overwhelming evidence. He was still a christian though... I think...
But that's all I can remember.