I keep saying this on channels, but I'm not sure I've mentioned it on here:
Floating treeview and floating switchbar options.
I tend to keep the channels I'm paying most attention to as desktop windows - around the edge of the screen while I'm doing other stuff. If I could minimise the main window, yet keep the treeview or switchbar on the desktop, that would be some more screen "real-estate" freed up
A thought I hadn't had previously - if it were floating, an extra option to dock the switchbar to a channel (either a specific one or the active one...) I suppose the same for the treeview, although I think I'd find it docking to the active window annoying, personally.