One of the more curious aspects of the Tory reshuffle (and there are several) was David Lidington's move from being in the Shadow Cabinet covering Northern Ireland to moving to becoming William Hague's Number Two outside the Shadow Cabinet, but with attendance rights.
I understand that William Hague will be taking on more responsibilities outside his Foreign Affairs brief, so needs a fully fledged deputy. Lidington was, of course, Hague's PPS when he was leader, so knows him well.
Quite what these new responsibilities entail for Hague I am still trying to find out, but maybe he will be doing more Party work (especially in the north) alongside Caroline Spelman.
UPDATE: Hague will be taking on a role in policy development. George Osborne will also be taking on extra campaigning responsibilities, as yet undefined.