As best as I can tell Alt+Tab/Flip 2D has not been changed in line with the new thumbnail/Aero Peek functionality of the Superbar.
This leaves it underpowered and inconsistent.
Note: working from online reviews - I haven't used 7, so apologies if any of this is already implemented.
Make Alt+Tab/Flip 2D a special case of the Superbar thumbnails that shows all windows/tabs in most recently used order.
Use progressive stacking/folding to aid location when huge numbers of windows are open (a hybrid of Flip2D and Flip3D). See wireframes attached, showing initial display and after a few tabs. Thumbnailed images show another variation on 3D effect for horizontal and vertical that keeps the icon visible even when highly folded and a stacking option that can be implemented without 3D graphics.
Use Aero Peek as you cycle through the thumbnails.
Degrade gracefully - delayed appearance so Alt-Tab is still instanious in the toggle case, thumbnailing from left to right after icon display, Aero Peek only if system remains responsive - I should be able to slide mouse across the thumbnails, or key repeat the tab key over the thumbnails. (see TaskSwitchXP for example of good behaviour)