There are also new Pokemon that will be revealed next week too which I think will be the starters for Pokemon Black/White 2.
They really should've just kept with 150. I stopped caring when they started adding more. Too much effort to follow.
You'll be surprised, but some people actually know all the Pokemon by memory lol. I need a Pokedex guide or something to help me remember some of them. I don't think Pokemon would still be around if they had just stayed with 150 Pokemon throughout all these years. They had to add more Pokemon if they were to stay in business.