If they could add random dungeons they would be a lot of fun, especially since so many people already know most of the dungeons by heart. They could just be randomly generated "kill boss" sort of quests.
They could have one scaled for each level, maybe after 5 to 10, and have different lengths.
There could be outside areas, sewer levels, or just mazes, with enemies and traps.
there would be different enemies each time and traps in random places. It would be nice if there was some new traps, like maybe a spike pit you had to jump over, or a giant rolling ball of spikes.
also for longer ones some minibosses before the end.
they would only have to make it for one level and just add stronger creatures for all the rest