If a game lives up to expectations, it certainly isn't overhyped. If anything, I thought it surpassed even the highest expectations placed on it. After all, the first one was a great game, without a doubt, but it was 'just' a great game without any real lasting relevance in gaming history. U2 feels like a completely different experience. The cinematic feeling is epic, and it's the most engaging game I've played in a long time. The fact that Naughty Dog crafted one of the most highly regarded games of the generation after the mere greatness of the original deserves all the praise, and more, than they've been received thus far. I don't think anyone could've predicted that it would become the premiere action/adventure experience available on consoles, that all future games in the genre will be compared too.
It's all about the game.