I think MT still needs a bit more time in the hot seat, but if the polls have not turned around 10 months from the election, Abbott should have a go. From the Spectator Australia:
As well as being the coalition’s parliamentary ‘enforcer’ as Leader of the House, Abbott was the former government’s intellectual in residence, churning out fortnightly articles for the Sydney Morning Herald, debating Julia Gillard every Friday morning on the Today programme, and giving numerous scripted speeches prosecuting the conservative side of the culture wars. Unlike a great many parliamentarians, Abbott is actually committed to core principles and values.
That would distinguish him from Rudd, who is like a schizophrenic actor in a multi-part play.