That's not likely to happen, especially any time soon...if ever. One of the biggest (if not THE biggest) draws to Pokemon is when new regions and new Pokemon are introduced. As long as these games sell, there will be more Pokemon. (Supposedly, GameFreak has over 1000 Pokemon already designed just waiting to be introduced at some point).
And when you say "make more games", do you mean spinoffs? The spinoff games aren't as popular as the main series.