I was thinking that instead of bringing back a full start menu, they could invent a whole new box. Let's call this a "spring box" (like the iOS spring board). The idea being that it only shows when the user is on the desktop (or it could be implemented across the platform) and be optional. When the user moves the mouse to the lower left corner of the screen (where the start button is currently) instead of just a button a small menu would pup up on top of the button and including the start button. The button, when clicked, would still take you to the start screen, but by just rolling over it, the spring box would appear. This box would contain up to 9 pinned live tiles OR DESKTOP APPS and no more than that. All the tiles would be that standard square size (like on the original Windows Phones) which could not be changed. At the bottom in a thin strip just under the user pinned tiles OR DESKTOP apps, would be small buttons that correlate to each charm on the charms bar (search, share, devices, settings).
If a user wanted to search he/she wouldn't even need to click the search button just like on that start screen. Instead the user would put their mouse in the lower left corner the spring box would appear and the user can just start typing, then the search pane would just appear on the right side, but the spring box would stay.
The right most button on that thin strip would be an arrow pointing to the right, when clicked the power user menu (Winkey+X) would appear to the right of the spring box allowing the user to shut down access those tools. These tools should not be able to be pinned to the spring box.
This idea would work as I realize the nine apps that the user needs to open constantly should be enough. The user would go to the start screen for other apps. Another thing implemented on the right corners are buttons, the top one opening the charms bar and the bottom one opening the PC settings. These buttons would be clickable like the start button and the app switching button.
What do you guys think? Any ideas you would like to see implemented?