I honestly dont know, I think chaos would exist, but our world might well be in chaos RIGHT away, however, we MAY or MAY NOT be able to fix it.
I would instantly seek out Riolu/Lucario.
The LEGENDARIES however may serve as a problem since they are one of a kind, all powerful and rare!
I mean IN THE ANIME Mew is cloned, thats in the anime, so imagine real world scientists and what they would want.
Basically, I think our world would function similar to the pokeworld, except we have no pokeballs since no technology exists (and I have no idea if it would) so befriending pokemon would be done by taming like in the Pokemon Conquest games.