I'll certainly agree that Gaim's UI could be a little better in this
regard, though I'm not too fond of Gaim's plugin UI.
Perhaps we could clone (well, not quite) the Add To Panel dialog from
gnome-panel, to have the name / summary appear as a bold header/plain
text sort of thing? It could be interesting to add icon support as well,
but I'm not sure that creating icons that neatly represent the
functionality of all the extensions would be a particularly easy job;
the Gestures extension would be fairly straightforward, for example, but
not necessarily so for the toolbar-extras extension.