Thanks for sharing this nice tip.
Glad you've found it, also applies to CS4.
Yeah, considering that the interface as a whole hasn't really changed between CS4 and CS5, I think it would be pretty safe to assume that
most of the capabilities in CS5 in terms of shortcuts and panels/tabs would probably be identical to the preceding version.
Much is the same between CS4 and CS5.
Scrolling the mouse not only works in the timeline but with all grouped panels.