I just released my first iPad only app. Sky Barons is a multiplayer iPad game that supports 4 players in 4 different playmodes.
Here is the iTunes description:
Dominate the skies from your plane! Chase after targets, race and battle other players in four unique modes of play. Multiplayer games with up to 4 players.
Leader board support provided by OpenFeint. Set high scores through a series of single player challenges.
iTunes link: http://itunes.apple.com/us/app/sky-barons/id439412560?mt=8&ls=1
If you'd like to try it I can send you a promo code.