Well, I come to like emerald version pretty much. It doesn't have the popularity it had in its 90's hayday, but come to think of it, the Pokemon games aren't the best RPG's, but they're pretty fun. Nintendo wouldn't be having that platinum version competition coming up if the pokemon games have lost their luster. A lot of people still like the pokemon games, and the emerald version (which wasn't released too long ago) proved the old formula still works.
Saying pokemon has no potential left is a false statement. Nintendo could make the games a bit better, but then again, a lot of people (even critics) have a heck of a good time playing them, so there's a good chance that pokemon is going to be around for a while. As long as they don't gum up the formula, we're good.