Well, the first Dungeon 2 details have been revealed by CoroCoro
Like the first game, there are two version; Time Exploration Team & Darkness Exploration Team, changing the mechanics from rescuing more to exploring more and getting treasure thats hdden away
The are to be 16 Starter Pokemon including Turtwig, Chimchar, Piplup, Pikachu & Munchlax. The rest will be known over time until release
There is a guild in the game which allows you to level your team up. It is run by a Wigglytuff known only as "The Master" with Chatot as it's top underling. Inside the guild there are various areas run by other Pokeon such as the Bidoof Area
It utilises the same engine as the past game so theres no graphical upgrade, but it is set to fully utilise the DS' capabilities. All gameplay from the looks of things is the same, but different areas, different dungeon and all the Pokemon in it in order for you to recruit them. It is due for release this Autumn.