I'm sorry Damian but I keep reading the title of this thread as "Diadem Needs a motorcycle".

Seriously though, a day/night cycle would be nice to have, but given it's an instanced area, there might certain technical challenges to it (I admit I'm not a crafter or gatherer and I only went to Diadem back when the original was first added in HW). It would still be a nice thing to have if they could though.