show client in mouse-over tooltip
the clients-icons plugin could show the name of the client along with the icon in other users' mouse-over menus, under the jabber id and resource name. that feature might be configurable, but it can generally be assumed that a users installing clients-icons plugin is interested in the clients, and given the number of icons available, users can't be assumed to know all client icons by heart.
i'm aware that said information is also available in the "personal information" dialog, but the whole point of the plugin is to make that information accessible more easily.