According to the official Pokemon website, there will be a major announcement on January 8. There are no other additional details.
Thoughts: This announcement could pertain to many different projects. However, some possibilities would make more sense than others. It would be too early for a new set of Pokemon. Typically, each generation lasts three years at a minimum. The fifth generation of Pokemon games was released in North America in March of 2011. A third game, or what Pokemon Yellow was to Pokemon Red and Blue is unlikely since Pokemon Black and White 2 served as sequels and answered the questions surrounding N, one of the main antagonists from the first set of games.
Some possibilities for this announcement include remakes of the Ruby and Sapphire games for the Nintendo 3DS that are compatible with Pokemon Black and White 1 and 2. For the two generations beforehand, the first and second generation games were remade to include the newer Pokemon and mechanics from the current generation. There is also the possibility of a 3D Pokemon game for the 3DS or the Wii U. This is plausible due to the new 3D models that were created for the 3DS via the new app Pokedex 3D Pro.
Final Notes: We will have to wait four days to see what the Pokemon Company and Nintendo decide to announce. This could potentially create momentum for the Wii U or the 3DS dependent on what is announced.