I'm not sure how much a longer warranty will help with keeping customers happy if they have to replace the keyboard every year and be out of service for a week or so while it happens. Heck, I was annoyed enough when my iPhone's battery started swelling and I had to spend two hours at the Apple Store to work through the replacement process. If I had to go without it entirely for a week, I'd have been nuclear angry and the fact that the repair was free would not have been too comforting.