No one on the current staff needs to be or should be the interim.
I'd rather go get a coach who isn't doing anything right now - Mullen, Mendenhall, e.g. - let them run the staff and program for the next couple of months while we start the search for a permanent replacement.
It would be akin to Rome getting Cincinnatus out of retirement to save the empire. Then let him go back to his farm - or house at Lake Oconee or whatever. or the blackjack table.
I was worried about Weinke's coaching ability when I looked at what he did with Jarrett Gaurantano at UT. He got worse every year. Sims isn't making any progress now either. I contend he was OK, not great, against Clemson. Less than 5 yards per attempt is not the mark of a great night quarterbacking.