For all you lucky Australians, or people with region 4 DVD players, it looks like the 3rd installment of the season one box set is now listed on Madman's My Little Pony page. I like how they are using the Comic Con poster too! These guys are totally aiming in the right direction with this.
Unfortunately, the actual volume 3 page is not available, but it does show a release date of August 1st. It looks like those of you with the collectors box will be completing your set around the holiday season at this rate.
Check it out on this page for now. Hopefully the actual pre-orders start soon!
Thanks to Dang0alot for the heads up!