I think Australia miss Ponting both as a batsman and a captain when he's not playing. His batting, as we all know, is excellent, and he's in supreme form at the moment. No one can doubt that an Australian batting order is considerably weaker without Ponting coming in after an early wicket, a late wicket or a wicket anytime during the innings.
His captaincy is also missed, but maybe not as much. There is no doubt he is a great captain, but whether his captaincy wins matches on its own is doubtful. Essentially, Ponting is picked in the team for his batting and not completely on his skills as leader of the Australian cricket team. Tubby Taylor was only in the team for his captaincy during that terrible form slump, and therefore his leadership would have been the only thing missed in his absense. When Ponting is rested, injured or not playing, his batting in particular is sorely missed, while his captaincy is not missed so much due to the leadership capabilities of Gilchrist, Hussey, Clarke etc.
EDIT: Argh, stupid random title that I don't want and is irrelevant to what I say in the post.