The Registry tweak I just did the other day increased the speed of the Aero Taskbar Thumbnails in Windows 7. The delay for the Thumbnails to originally pop up was about 2-3 seconds. Now there is absolutely no delay. I like to switch between windows rather quickly, and when I have several windows up all from the same program, having a delay is just annoying.
Increase the Speed of the Aero Taskbar Thumbnails in Windows 7