Well, that was quicker than we expected. Less than a monthafter its US launch, iTunes Match has gone live in Australia, costing $34.99 a year.
For that money, you get anything in your local iTunes library accessible via the cloud; songs already in iTunes are available automatically (and potentially at a higher bitrate than your own copies), while more obscure items will be uploaded. It's a tempting possibility, though bear in mind that you could chew through a lot of data on the initial upload if you have a large collection (though there's a 25,000 song limit).
iTunes Match [iTunes Store]