Still I do not understand why they would only add 70 new pokemon. However, like people have said that is 70 pokemon in the first 2 areas, about 35 per area and no one has made it to the 3rd half yet. It may be another 35 in the mountain area, making the total 105. Which would be alright. Remember that the Pokedex book thing for Kalos is said to have over 800 pages. Which usually they only show new pokemon in that book, but there is a lot more stuff now.
I am saying there will be at least 35 more pokemon for mountain area. If so, that brings the total to 754.
This is the transfer to 3DS, not to mention they have added a ton of old pokemon to catch. I think 105 is a good total. I am surprised that Oorotto and Noivern have not yet been spotted in the wild.