I've been planning this concept for a while, but haven't had the time to put it together. So, here is a preliminary image to show what I've been working on. There is a little refinement that needs to be done, but overall this captures my thoughts for Threshold.
Notice in the Taskbar how after the first 5 apps there is a white bar. This divider between the groups of apps represents dividers between desktops. I really hope they keep all apps visible in the taskbar and make only a small distinction between the desktops like this (I feel like it would be less like playing "where's my app?"). You could then zoom out to see a summary of all your desktops and running apps by double clicking the "Show Desktop" button in the lower right corner.
Also notice the last app section on the taskbar that has the IE, File Explorer, Zune (wishful thinking), phone, and messaging apps. This is your phone with Microsoft apps synced. I feel as if this is the best implementation of "continuity" or "handoffs"- like features in any operating system. I forgot to place it, but before the last divider there should be a battery and connectivity symbol that will display some brief information about your device. This continuity-like feature would be great for other devices that you have running under your Microsoft ID including phones and other computers (or Xbox for that matter).
Dear Microsoft,
Please do not eliminate the charms. Yes, I believe they were poorly received on the desktop and in general, but they are a great way to access information in the same way across every single app. I understand the need to remove the charms bar for mouse/keyboard users, but perhaps you could simply re-implement them in a different area. I think you should keep it the same for tablet users.
In a future post I will give a little more detail as to how I would like to see charms uniformly implemented, but briefly it'll just say that it would be a great idea to have them in the jumplists on the taskbar.