Platform for Ace Attorney 5 has not been announced, Ace Attorney 123HD (Ace Attorney, Justice for All and Trials and Tribulations compilation) will be for iOS platforms. No release dates have been announced.
Games were announced at a Ace Attorney 10th anniversary event. Capcom had said they had plans for Ace Attorney in 2012, but I wasn't expecting anything significant.
Now two things: I hope this gets localized here and WHERE THE FUCK IS ACE ATTORNEY INVESTIGATIONS 2 FOR NORTH AMERICA.