The Xperia S is one alluring looking phone. Alluring but to date a little hard to pin down. Worry no more — it's coming soon to just about every carrier and mobile phone store in Australia. Update: Optus has announced its contract plan pricing. Sony's just sent out a release lauding the Xperia S. Pricing and plans aren't set at this date, but in terms of availability, Vodafone and Crazy John's will have it on April 11, Optus will have it in "early April" — I'd be guessing the 11th as well — and it'll be available for outright purchase from JB Hi-Fi, Dick Smith Electronics, Allphones, Telechoice and Harvey Norman, although it's not clear if those stores will have it in April. Given JB Hi-Fi is usually a Telstra-exclusive store, it's a reasonable bet that it'll work across carriers.
Update: Optus has just announced its contract plan pricing for the Xperia S, although it's still stuck with "early April" for availability.
$0 upfront handset repayment on the $49 Optus Cap Plan for consumers (24 month contract, min total cost $1176) $0 upfront handset repayment on the $49 Business Complete Plan for businesses (24 month contract, min total cost $1176)
The release notes that you can pre-register with Optus here, although at least at the time of writing, that link seems to be down. Presumably you'll be able to pre-register there at some point.