Windows 8 is a long game. The right metric isn't success (however it's measured) in the next three months--it's the next three years. Windows on clients will be a fundamentally important technology for a long time to come, and so what Microsoft does here really matters. Given the magnitude of the change, though, it's going to take everybody a while to work out how that change should look, which is what's driving the updates in Windows 8.1 and the rapidly morphing form factors of Windows 8 devices. We're sure to see more change before things settle down.