The current loot system--if I'm understanding it correctly--does not allow for high-level monsters to have things like a bag of tricks. Instead, it automatically gives players a magic item of level X, then level X +1, then level X +2, etc. With monsters like dragons (who traditionally have a vast quantity of items), it is logical to assume that there would be some low-level magic items thrown in with the "big ticket" things. However, this doesn't happen in 4e with the parcel system (as I understand it; correct me if I'm wrong).
In previous editions, players could get treasure they didn't need because treasure was rolled randomly, so even a balor could have a +1 longsword in his junk closet.