It will also be interesting to see if he appoints a Deputy PM. He obviously didn't have any choice within the coalition but most Prime Ministers have preferred not to appoint a deputy although, of course, Tony Blair chose to do so (or, it seems far more likely, was forced to do so in return for a promise of loyalty from Gordon Brown).
So will anyone in the Conservative Party be powerful enough to get the Deputy PM's job? I note that the BBC website doesn't list it as a Cabinet post waiting to be filled:
http://www.bbc.co.uk/news/election-2015-32658697