Yeah, plus he is indebted to Harry for that. Remember when Dumbledore said that Harry sent Voldemort a wizard who is indebted to Harry, when one wizard saves another there is a certain bond between them, which is absolutely what Voldemort wouldn't want, a servant in Harry's debt. He also predicted that there would be a time when Harry would be very glad he saived Pettigrew's life.
I am hoping that Pettigrew will step in front of Harry when Voldemort gives the death curse, giving Harry a chance to kill Voldemort. Hehehe...maniacal laugh...
That would be awesome! LOL!!
AS, I didn't even think about Greyback. I always assumed the silver hand was for Lupin. Plus, we have Bill with werewolf-like tendencies. I hope we don't lose too many Weasleys!