The difference between the two environments, at least on the desktop, is jarring. As the author points out, on the Metro side, the desktop is just another tile.

The difference between the two environments, at least on the desktop, is jarring. As the author points out, on the Metro side, the desktop is just another tile. Strange. And on the desktop side, they've removed the start button, so the taskbar looks incomplete. To go to the start screen, you either need to move your mouse to the bottom left corner to reveal the start screen icon as a hover/tooltip sort of element, or the bottom right corner, which brings up the charms bar with the start button. In both cases, it's move/hover/click. In both cases, not self evident (like a button!?) and not super discoverable. This makes more sense on a touch device but it's not so great for mousers (e.g., the people who will run the desktop version in the early days, a.k.a nearly everyone). I'm guessing (and hoping) that they have a new alternative to the classic start button planned for a final reveal in RTM that will take you directly to the start screen. It'll be interesting to see how this is solved over time. I imagine Windows 9 will have most of the usability issues solved. In the meantime...