I'm certainly under the impression that if Northern Rock were to go bust, the loands and mortgages on their books would be simply sold on.
I have a small personal loan with Northern Rock, so I made sure I read about such a situation carefully in the various news reports coming out - and from these, I'm given every indication that I will be paying that loan off to completion, either to Northern Rock, or any other company that administrates the debt owed.
Hope that helps, and welcome to Finance Markets.
