If Pokemon existed in the real world, I would be utterly terrified.
As much as I love Pokemon, there are too many bad people out there who would use Pokemon to commit horrific crimes. Murders, robberies, "natural" disasters (Earthquake, Twister, Thunder, etc.), and even things like genocide would probably be even more catastrophic than they already are.
I do however believe that there are many more good people in the world than bad, but I don't think that having more good people than bad would lessen the massive damage that horrible people like that could do if they were able to control such terrifying power as that of Pokemon.
Not to mention you'd probably run a huge risk of being slaughtered by wild Pokemon. You'd be eaten by a Luxray or your house knocked down by an Ursaring or something.
And if Pokemon existed in this world, then the "no dying in battle" rule would be non-existent. I couldn't imagine becoming so immensely close to a Pokemon only to have it die in a Pokemon battle. That kind of loss would be devastating.
So all in all, I would never want Pokemon to exist in the real world. No, thanks.