Before you downvote this. Mewtwo and Genesect. The only 'created' Pokemon. The rest are all natural >:D
No but seriously, there are 649 entries in the pokedex. 650 counting Victini. Counting alternate forms, add the therians, kyuremb/w, keldeo's alternate form, sky shamin, giratina's other one there are 658. There might be a couple more I neglected but yeah, over 650 Pokemon in total.
Also factor in the current 25 announced X/Y Pokemon.
After Pokemon X/Y comes out there will be well over 700 :D