There seem to be many signs pointing to a future 5th-Generation sequel, which for now I'll call "Pokemon Gray". This is all pure speculation based on currently-available trends.
Post here with your own speculations.
- Kyuremu will be the mascot of Pokemon Gray.
- The Battle Frontier will return. An extra Subway train will take you to the other facilities.
- N will use a team of six non-legendary Pokemon to fight you before he summons Zekrom and Reshiram. Kyuremu will take you and N to a frozen land, much like the Distortion World, where you will meet with Kyuremu. Once you've caught Kyuremu, you will be taken back to N's castle, where Geechisu waits for the story of N's success. When he finds out that N had failed, he tries to finish it himself.
- And more!!
Post here with your own speculations.