I picked up this picture on Flickr. The far tracks are the lines out of Marylebone. They are not electrified and there are no plans for electrification on this route, which runs only as far as Aylesbury.
At one time it was part of the Great Central and trains ran to Rugby, Leicester, Nottingham, Sheffield and Manchester. The route beyond Aylesbury is largely intact and could be reinstated at relatively little cost as a conventional railway to provide the additional capacity that HS2 advocates insist can be provided only by constructing a high speed line. They assure everyone that it would cost just a teeny-weeny bit more. That sounds implausible.