It seems that Apple has decided to put a neat feature in Japan’s version of iOS5! While the poster says this will drain the battery down, I don’t think it would be nearly as bad as he is implying. Of course, I don’t know exactly how the earthquake notification service actually works, but I suspect that it would function best as a Push notification. When you think of it that way, almost all your Apps have some form of Push notice, so what’s one other app the accepts Push? A live 3G connection to a website status would seem horribly taxing (and actually would drain your iDevice battery very quickly). I guess the best question to ask if it does rely on Push is if their server can push out a million notifications in mere minutes?
Apple puts earthquake warning system in Japan’s iOS 5 | Japanator.com