According to Niantic Labs' John Hanke, the current game is only 10% of what the teams wants the finished game to be.
Niantic is planning some big things for Pokemon Go in the future, assuming they can keep the servers working. Niantic confirmed at Comic Con 2016 that future updates will include training and new Pokemon, as well as the inclusion of Pokemon Centers and PokeStop customization.
Also unveiled at Niantic's Pokemon Go Comic Con panel were the faces behind Team Valor, Team Mystic, and Team Instinct - Candela, Blanche, and Spark. In addition to showing off the Team Leaders, Niantic confirmed that the legendary birds are, in fact, tied to teams. Somehow.
Niantic's John Hanke also confirmed the Eeveelution Easter Egg (naming your Eevee Sparky, Rainer, or Pyro before evolving it will result in a Jolteon, Vaporeon, or Flareon, respectively), but also teased that there are other Easter Eggs in the game - and they're ones that no one has found yet.