As far as the singleton/Reno style decks I'd like to see them print more "Regrowth" style effects like in Magic. Currently there are a few cards that do this in Priest/Shaman but once Reno is gone the Highlander deck reverts back to a one trick one and done pony. Having the ability to recur both spells and creatures, randomly and selectively would go a long way to giving that style of deck legs beyond of course just reprinting Reno.