Sighted at a couple of Target stores in NSW and QLD, are the Preview figures Bumblebee and Soundwave. Price at Target is $29.

At Toyfair they said the Preview wave should be out around May 15th, so expect more stores to have them in the next week.

The main line has a release date of May 30th, and Hasbro would be sending out stock in the weeks leading up to that date, so you might find some stores putting out their stock as soon as they get it.