Meaning Ernie McMillan (CoS), Zacharias Smith and Seamus Finnegan are all lining up to be DEs as well. But I supposed they've all went through the Redemption already, by believing Harry in the end.

Yes, indeed, come to think of it, you are right. They were on that slippery slope leading straight to Evil, but were redeemed by Believing - by having faith in Harry. (Excuse me while I retch.)

I don't even want to think about Percy. I suppose he'll be made to grovel something awful before being allowed "back", and I know that's the point where the book will hit the wall.