@evildictaitor: You mean I can make them overlapped at any size, like we've been able to do for the last 20 years? If you can tell me how I'll give you a dollar.
I'm aware of the option to dock them on the side, but it's useless. The IE app just doesn't lend itself to having stuff on call while I'm developing in VS. I can't even really put it on the second screen, because if I do that, all Metro stuff (including the start screen) moves to that screen, which is just the stupidest thing ever.
I'm on a regular desktop PC, with two large monitors. I simply see no reason to ever have anything run full screen. And docking it on the side is nice in theory, but then it pushes the entire desktop aside, and I can't put any windows on top of it without first undocking it again. Plus, there's a pointlessly huge border dividing the docked app and the rest of the screen (I'm using a mouse, I don't need a 10 pixel divider).
Metro is nice, I'm sure it's great on tablets, but I simply have yet to discover anything I would want it for on the desktop. Every time I find an app that's potentially nice, the same thought runs through my head: "if only I could run this in a window..."