Comment 51 for bug 527458

I desperately miss the tooltip of master volume! :'-(

My argument for "tooltips everywhere!":
Tooltips are most valuable for newbies. And the more tooltips there are, the more users get aware of them. If all but the most important tooltips are removed, users won't wait anymore on every widget, because most of the time nothing happens.

In short: tooltips only make sense if they are common enough.