Aldur is usually assumed to be a Druid of old by fans of Diablo, and his name is a popular one for Druids in Diablo fan-fiction called Winds of the Kae Huron.
His “Watchtower” may refer to the Túr Dúlra (“Tower of Nature”) which is said to be the greatest of the Druid colleges.
Aldur’s Watchtower is a moderately good set in theory, but the high level requirement of 76 on the body armor prevents this set from being of much use. The damage on Aldur’s Rhythm is fairly good for its level (42), but it’s inadequate at best once you can wear the body armor.
The full set bonus yields 350% Enhanced Damage, but this does not function as it does as it would on the weapon. The 350% bonus is added to skill and attribute damage bonuses instead. This is confirmed to be not a bug, but a balance factor.
Aldur’s Watchtower Item List
These are the items of the set, listed with all their stats. For more information, visit each individual page.
Aldur is also the name of a god in the fantasy series The Belgariad and The Malorean by David Eddings. He incidentally also started out living in a watchtower, as did his disciples in knowledge and magic. It’s very well possible someone within Blizzard North enjoyed the books enough to give him a cameo.