Hmmm, this could be another tough tie.
The only rubber that Australia is virtually guaranteed to win is the doubles, with or without Hewitt's help. Otherwise, much depends on how fit Hewitt really is. If he is okay, he should beat Darcis...also Rochus, but that one could actually be a real dog fight.
If Hewitt gets Australia off to the perfect start, Ball has a good opportunity to add to his credentials. He'll need to play some of his best tennis, though, to beat Rochus...Olly a solid favourite. Failing that, he has a better opportunity against Darcis.
I'll go with a 3-1 win for Australia (if Hewitt is fit he'll guide them through), but not sure about the dead rubber.