Picked this up today, and have been playing it non-stop ever since. It was definitely worth the wait.

Portal 2 is a bigger, and better game than its predecessor. With new puzzles, new environments, and new ways of solving these obstacles, it stands out as one of the biggest brain busters in terms of gaming. Everything else in the game such as graphics, sound, controls, and the game's dark humor are fantastic too.

There's really not much else to say about Portal 2 other than it's truly an amazing game. If you liked the first Portal, then you have to get this.