I think rather than a Roulette, this could be better handled as a Daily Challenge. Right now the only thing we have for that is PvP/Frontlines, but you could have something like;

Daily Challenge: Minimum Item Level Dungeon
Daily Challenge: Minimum Item Level Raid
Daily Challenge: Minimum Item Level Trial

Complete with a set of achievements for completing such content (the current Daily Challenge: Frontlines rewards you with a mount via achievements, for example).