If we are getting DPL, then the set will have 3 Legends...which seems a bit unlikely considering we would only have Cresselia/Darkrai for our fourth set.
The press release for Undaunted mentions Groudon/Kyogre and Rayquaza/Deoxys:
"No Challenge Too Great, No Battle Too Fierce: HS—Undaunted
The greatest Trainers are those who are fearless in the face of battle. And that’s you! In the Pokémon TCG: HS—Undaunted expansion, you’ll discover battle-ready Pokémon just waiting to be summoned by the fearless Trainer in you! The powerful Rayquaza and Deoxys become a Pokémon LEGEND to be reckoned with...six Pokémon—from Raichu to Umbreon to Slowking—join the ranks of Pokémon Prime...and Stadium cards like the Ruins of Alph and Trainer cards like Legend Box change every player’s strategy. Are you ready to be Undaunted?
HS—Undaunted features 90 new cards and remains compatible with previous releases.
• Exciting new Pokémon LEGENDs—Kyogre with Groudon and Rayquaza with Deoxys! • Six Pokémon Prime, including Raichu and Slowking • Brand-new Trainer, Supporter, and Stadium cards with new gameplay strategies! • Features two theme decks built around the Sun Pokémon Espeon and the Moonlight Pokémon Umbreon • Each theme deck now contains a BONUS booster pack and a deck box for storing the deck! • Holographic parallel set for players and collectors alike • 90 cards in all!
In Stores August 18th, 2010!"
The press release for Undaunted mentions Groudon/Kyogre and Rayquaza/Deoxys:
"No Challenge Too Great, No Battle Too Fierce: HS—Undaunted
The greatest Trainers are those who are fearless in the face of battle. And that’s you! In the Pokémon TCG: HS—Undaunted expansion, you’ll discover battle-ready Pokémon just waiting to be summoned by the fearless Trainer in you! The powerful Rayquaza and Deoxys become a Pokémon LEGEND to be reckoned with...six Pokémon—from Raichu to Umbreon to Slowking—join the ranks of Pokémon Prime...and Stadium cards like the Ruins of Alph and Trainer cards like Legend Box change every player’s strategy. Are you ready to be Undaunted?
HS—Undaunted features 90 new cards and remains compatible with previous releases.
• Exciting new Pokémon LEGENDs—Kyogre with Groudon and Rayquaza with Deoxys! • Six Pokémon Prime, including Raichu and Slowking • Brand-new Trainer, Supporter, and Stadium cards with new gameplay strategies! • Features two theme decks built around the Sun Pokémon Espeon and the Moonlight Pokémon Umbreon • Each theme deck now contains a BONUS booster pack and a deck box for storing the deck! • Holographic parallel set for players and collectors alike • 90 cards in all!
In Stores August 18th, 2010!"