The Samsung Australia website is now offering accessories for the Galaxy S III. Currently you can get:

Galaxy S III Desktop Dock : $49.95
Galaxy S III C Pen Stylus : $29.95
Galaxy S III HDTV Adaptor : $39.95
Galaxy S III Flip Cover : $34.95 (Available in Blue or White)

Shipping is extra so take that into account, also when trying to purchase any of the accessories you’ll be advised that Samsung is expecting stock on hand on the 6/15/2012 so hopefully if you order tonight your order will ship tomorrow. no sign of any desktop or car docks, spare batteries, cases, S-Pebble or the wireless charging adaptor which is said to not be available till September.

Galaxy S3 Forums via Samsung AU