I'm betting this election will be really close, down to a seat ot two either way.
IF Rudd wins - any law changes will have to get through the Senate as well.
Rudd could win by 1-2 seats (or more) and still not get Senate control.
Family First, Pauline Hansen and a couple of fringe dwellers could pick up Senate seats and along with the Libs and Nats could band together and block supply.
Double-Dissolution and we are back at the polls again in a few months......