I did do a quick search, and found no mention of G4 breezies being available in retail stores yet.
I just bought two loose on ebay, and was wondering if they had been released anywhere - basically if I got ripped off. Although I only paid $3 each, so I doubt it, but they have different antennae colours to the fair pictures, so I'm assuming the fair ponies were protos, and not the actual release ponies.
At any rate, you can get them on ebay, if you're so inclined, and don't wish to buy yet another Fluttershy or Twilight, and aren't interested in the locket bits and bobs.