I would guess there is already someone working on this but... I would love to see a UI or launcher customization app along the lines of the old windows TweakUI apps.

In particular, being able to add launcher pages (without the current rooting method), being able to assign and save brightness settings for screen when on the touchstone, icon size (is it possible?), wallpaper controls, ability to replace the launcher icon from the main grouping (is it possible?)

probably other practical or cool customizations that I'm not thinking of at the moment could be included too.