Support items using the new Jungle model would really mix things up bot lane.
What if you separated the stats from the gameplay effects of the support items and used enchants on them ala the new jungle stuff? For example, someone can buy the frostfang line because they are pokey, and then enchant it to be a defensive item with HP/cdr or something instead of mana regen/AP. This could really open up the support slot to be able to really help fill what the team may be lacking elsewhere.