Chip industry
The consolidation of the industry will find its natural level. Even a "natural monopoly" is not immune to all market forces. Note that Intel and AMD are not exhibiting stereotypical monopoly behavior, i.e. turning out lousy product at high prices because there's no choice for consumers. Both companies are busting their chops to stay on the razor edge of technology, and I don't think it's just to stay ahead of each other alone.
Keep in mind there are a lot of countries out there that could also open chip plants--American corporations like IBM, GM, and electronics companies learned the hard way some years ago that they are not immune to someone overseas eating their lunch.