Earlier today, Pokemon GO developer Niantic announced the addition of 23 new Pokemon to the game world. A few of these Pokemon can be seen in the image accompanying the post. if we include the evolutionary line of these Pokemon, that means we can safely assume that the following can now be caught in the wild.
This is only 15 of supposed 23 available Pokemon. The only for sure way to figure out the remaining 8 Pokemon is to actually go out and see them. However, the Reddit Community, Silph Road, have some educated guesses.
The logic here is that the image and the Pokemon therein are all desert/caved themed. These 8 are other 3rd generation Pokemon that fit that criteria that were not seen in the image.
The factual accuracy of these guesses will be tested soon enough.