I've heard, > in August, we’ll see the MLP: Celestial Solstice Deluxe Set arrive. The deluxe set features a fancy storage box for all of your cards, two oversized Mane character cards, 24 exclusive foil cards (three each of eight new cards), 6 card packs, deck protector sleeves (I believe Celestia & Luna), and a poster identifying every card released thus far, as well as a d20, all for $29.99
Also heard rumour that the two additional new foil Mane Character cards will be new versions of Princess Celestia and Twilight Sparkle (I hope Princess Twilight Sparkle!)
Update - Aug. 15/14
I like it when I'm right! :)
According to MLPCCG tournament tumblr website, Celestrial Solstice Deluxe set is premiering on August 14-17 at Gen Con. I can only assume it's release date with follow.