Its a good idea imo, it would really make it feel special to find that awesome legendary
But they'll definitely need to improve on it. Maybe limit each item to be traded just once to whoever you want,
or just make the very best gear soulbound. It does feel a little extreme to make all legendaries 100% soulbound since they don't seem to have any plans replace the AH with some other kind of trading function anyway which would make it alot harder to find the right trade.