Democracy and the retirement of Prime Ministers

I am getting frustrated with the Labor leader's constant attempt at scare-mongering regarding the possibility that Peter Costello will be the next Liberal Prime Minister. In response to a cabinet reshuffle, Mark Latham took the opportunity to again raise the issue of whether or not PM John Howard will stay on as the leader of the government for the full term. The AAP quotes Latham:

"Mr Howard has today clarified a handful of ministerial positions. He now needs to clarify his own position.... If he wins the next election, will he serve three years or, as most people expect, hand over to Prime Minister Peter Costello? Ministers Kemp and Williams are retiring. Mr Howard needs to be honest with the Australian people about his own retirement plans. Our democracy deserves nothing less."

Australian democracy, of course, is parliamentary and not presidential -- the public votes for a party, and the party determines their parliamentary leadership. The election should not rest on personality politics of who the public want as PM, it should be about the respective policy platforms that each party proposes.