Well, I think that stating Honda's will last forever is being a bit overzealous. I would estimate that if taken care of (regular maintenance items completed up to 150K, and then repeated after that), the engine should be quite reliable upto about 300K. When you go above that, regardless of how well you maintained any car, problems due to unavoidable deterioration and materials breakdown will become dominant - you'll eventually start having problems.

But, if you are keeping your car longer than 350K, the little problems become less noticeable and you still feel as though the car is 'as good as new'.