"you can’t give iOS apps even the option to run continuously in the background without sacrificing battery life and foreground app performance. But that’s how Microsoft has positioned Metro for tablets — a modern touch interface that carries the full CPU and RAM consumption of Windows as we know it. That have-your-cake-and-eat-it-too attitude is what I didn’t get with Microsoft’s positioning Metro as its answer to the iPad."
This is wrong. From Anandtech: (http://www.anandtech.com/show/4771/microsoft-build-windows-8...)
"discarded applications will continue to stay open as a background application, having all of their memory pages intact but unable to schedule CPU time so long as they’re a background application. They’ll remain in this state until the OS decides to evict them, at which point they need to be able to gracefully shut down and resume when the user re-launches the application. Internally Microsoft calls this freezing and rehydrating an application."
Metro's approach sounds very similar to that of iOS and Android. Presumably this behavior will be adjustable so that background processes can be allowed on desktops without mobile power constraints. This is actually a really smart way to do things. Make how the OS handles background apps a setting rather than hard-coded architecture. e.g. If you're out and about using your tablet background apps get quashed so that you get decent battery life. When you go home and plug it into a dock you can leave a torrent downloading in the background while you browse the web or play games. Best of both worlds.