I think, following the events of 'The Magician's Apprentice', the Doctor will go back in time and kill Davros, therefore the Daleks will never have existed. So Clara is alive, although the Doctor's actions will have created a massive paradox. The paradox can only be sustained for a while (ie. the whole of series 9) before the Doctor has to do the right thing and revert time back to normal, therefore sending Clara to her death. That's my favourite theory.