DS title Pokémon Platinum details are divulged in the August issue of CoroCoro comics. Besides announcing official Japanese release date is September 13th, there's a bunch of new details like a new "Wi-Fi Club" area that's able to hold up to 20 folks at once, a new Team Galatic member, new international police member, a "Battle Recorder" that allows trainers to record and share battles, and Dialga and Palkia appearing simultaneously in story.
CoroCoro [Filb.de via blue skY via Moetron]