Australia ALWAYS played with four bowlers. Watson only recently broke into team after Symonds' antics. Pakistan team of yester years also played with four bowlers and won everywhere.
However, they key here is to play four good bowlers on form.
I hope they play the following team (considering Younis is not going to be there)
Farhat Butt Malik Yousuf Umar Misbah Kamran Aamer Asif Kaneria Saeed/Gul
I like this team. But the thing is would Yousuf give Malik the ball? It was Akmal who tried Farhat for a few overs in the last match when Yousuf stepped out of the ground. I hope he tries Farhat/Malik even just to rotate the bowlers.