Name's the Same: The title character was inadvertently named after a comic character from The Forties who would feature in US Air Force publications as a humorous example of 'How Not To Do It'. Adams asked for name suggestions from his friends, and the winner didn't realize he must have recalled the name from the earlier comic until after Dilbert had already become famous.
Hey, It's That Voice!: Several of the voice actors are well-established, as are some who aren't commonly known for voice acting but can still be easily recognized from their many live-action roles (Kathy Griffin, the voice of Alice, is uncredited for some reason), but the Garbage Man is voiced by Maurice LaMarche, who is in many, many animated works and games and can be recognized from the Garbage Man's voice as such varied characters as The Brain, Kif Kroker and Morbo, and Abraham Lincoln.
Screwed by the Network: Despite the show's high ratings (by UPN's standards), the show was canceled due to the network's decision to focus entirely on minority groups (primarily African-Americans) in the station's line-up, notably the show that aired right before Dilbert, Shasta McNasty. The fact that UPN went off the air shortly afterward shows how good an ideathat was.
For its second season, the series had also been moved from its fairly successful Monday night timeslot to Thursdays - up against NBC's then-quite powerful lineup.