I don't think we need those. They're only good for making the Memory runeword, and I'm rather unimpressed by its stats, especially compared to an Oculus or a Chromatic Ire. So I don't think I'd ever actually use it, and runewords aren't collectible ;) .

OTOH, I think a two-socket staff could be useful, though the staff would need +3 inferno (and preferably +3 fire mastery). With this bonus and the Leaf runeword, it'd have +9 inferno on just that item; it'd be a rather nice item, then, for an inferno sorc :) .