Koei Tecmo have added costumes for Twilight Princess & Skyward Sword to Hyrule Warriors.
The new costume pack features a change of attire for both Zelda & Link and the new items form part of the Courage costume pack, which is included with the Premium Box and Treasure Box versions in Japan. More costumes could be on there way to Hyrule Warriors too since there are also Power and Wisdom costume packs included with the Treasure Box. Its not known yet if these will be released individually at some point or whether they'll form pre-order bonus content for the games release in the west, if the Limited Editions in Japan don't make it to our shores. We'll have to wait and see.