Too bad it doesn't work anything like the videos.
Translations are about 50/50 on whether they make sense, it can only read large, easy to read text (like headlines and large street signs), it is NOT free ($5 for each language, in ONE direction. Soon to be raised to $10!), and it doesn't always replace text properly.
Frankly, Google Goggles has allowed people to take pictures of text and translate it for a while now, which although it isn't augmented reality-style, it is pretty fast, far more accurate, FREE, works with tons of languages (even non-latin based), and doesn't have as much trouble reading text. Oh, and you don't need an iPhone.