Pokémon Brilliant Diamond and Pokémon Shining Pearl spoilers have begun making rounds online, so be careful out there. Be sure to stop reading this post if you want to avoid seeing spoilers. The following info comes directly from the Centro LEAKS account on Twitter:
– No new forms, moves, megas, characters, events, or anything so far.
– All the trainer teams are based on the DP teams, not the Platinum ones. Levels too.
– That also means your team will be overleveled because of the new EXP system.
– Gym puzzles are also based on DP it seems.
– No Platinum-exclusive characters.
– However, movesets have changed.
– Pokémon now have different cries when fainting.
– Most of the battle music in the game is unfinished and sounds terrible, hopefully is going to be patched.
– There are multiple visual glitches in the game, probably going to be patched.
– Many Pokémon have new idle animations, based on their DP sprites.
– Having your Pokémon follow you will raise their friendship very quickly, so it basically works as an “easy mode” as it will gain EXP more quickly, dodge attacks, etc.
– The original DP HMs are now TMs.
– TMs are single use again, trainers like Gym Leaders give you multiple.
– You can still play music notes with your badges!
– You can still customize the dialogue window border like in the original games.
Source: Centro LEAKS @CentroLeaks