This very much depends on how this would come to be. If it was a sudden change, in which Pokemon and all related items and resources just came into being one day, it would be literal hell. Hundreds of different creatures many of which have the powers of gods just show up one day, and in doing what they normally do, we would suffer, as our world is not prepared for it. However, if it where to be that we all lived in the Pokemon universe, then that would be pretty cool. I feel like it would be a lot like it is portrayed in the games and show. Life would be interesting, getting to catch, train, and befriend wild animals, and use them to fight other people who are doing the same thing. The only real down side I can think of is that the wold could end at the drop of a hat, though there will probably be a 10 year old that just so happens to be in the right place at the right time and save the day.