Check out the logo of the just announced Pokemon Black/White 2, the first numerical sequel in the main Pokemon series. Those colors are Ruby and Sapphire which happened to be the third set of Pokemon games that released for the Gameboy Advance. When Diamond/Pearl were released there was context hinting at the eventual Heart Gold/Soul Silver. Black and White has had some references pointed at the next in line to be remade, Ruby and Sapphire. Also interesting is this game for Nintendo DS and not 3DS.
Another interesting thing is that the legendaries for each game look like Zekrom fused with Kyurem or Reshiram fused with Kyurem. For those who don’t know, Zekrom and Reshiram were the big legendaries of Black and White and Kyurem was the third in the set. While that is extremely interesting, we can’t forget about all the new Pokemon that will hopefully be introduced in the new games.