dude,
do how many overs murali bowls for sri lanka, ever wondered why spinners are often leading wicket takers, because they bowl heaps and heaps of overs. murali is like the only bowling attack sri lanka have got and they use him a lot, like on he will handle 40 overs easy. as for kumble he is old but has an excellent record aggainst australia. vettori isnt as good as a spinner compared to muralia or kumble he is a better a batter and fielder but that really isnt what you r looking at this level.
the test 6 days but doesnt mean it will last 6 days, i would 4, depending what bowlers are selected for australia and world XI. for asutralia lee,mcgrath and warne with gillespie who can expect it to be over within 4 days, that is not to say australia will win.
of course recently the batter have been better but the scg compared to the other ptiches is the least batsman friendly to australia.
as for the one dayers, mayble vettori will replace kumble, he a better player in one dayers.