In addition to Ace Combat: Joint Assault, Namco Bandai has another Ace Combat game in development. The publisher trademarked Ace Combat: Assault Horizon for use with video games, ROM cartridges, and the like in Europe.
This is just a guess, but Assault Horizon seems like a console Ace Combat game. Namco Bandai already made an Ace Combat Xi: Skies of Incursion for the iPhone and Ace Combat: Joint Assault is for PSP, which was also trademarked before it was announced. The last Ace Combat game for consoles was released in 2007, Ace Combat 6: Fires of Liberation (pictured).
But wait, if Project Aces is working on Ace Combat: Joint Assault who is developing Ace Combat: Assault Horizon?