> It's useful if you have stuff on the desktop (like I do). If the desktop is nothing but wallpaper space, then minimizing windows make little sense - just get your windows on the front (which is hard to do without a dock)

At times (especially at work) I will have many different windows open at the same time. Exposé at that time will become very cluttered and it will be very hard to find the window I want, minimising removes that because now the windows I do want are bigger than the small minimised ones.

From looking at more screenshots from Gnome 3 it looks like their "activities" overview is a lot like Exposé.