But what does that mean? Fallout and Witcher have different approaches to open world, and both are fairly different from what XBX does.
I'm excited for this game, but I fail to see what makes the open world in the game all that different from a really pretty MMO. No loading times is a really cool feature, and it is absolutely drop dead gorgeous, and I'd even say arguably more gorgeous than F4 and W3. (Well, F4 for sure, Witcher is debatable, but I really like XBX's art design). For all intents and purposes, I've seen XBX as an MMO with a robust offline mode. It uses similar quest design, has a very thorough loot system, and it even locks you from having a mount until you reach a certain level. Now, it may be one of the best MMO's ever, but beyond being beautiful, I've yet to see what's so innovative in its world, other than size.
That said, W3's open world is actually its weakest element, it doesn't serve much purpose beyond being an incredible setting for a really good narrative adventure. I'm not saying the guy is wrong, but I guess I just need to read the review to see what that means beyond pointless hyperbole.