Been decorating my flat all weekend, and beating some general fanedit ideas around my head.

What if (and this discounts PT canon) Darth Maul is introduced as Obi-Wan's fallen ex-apprentice? It would require some exposition and dubbing, but could lead an audience to think he is Darth Vader later on, and could provide a motive for his vengeance against Obi-Wan.

Its a real shame we never see Anakin fighting him really, but the whole subplot could get introduced verbally in Ep I, then we meet the guy in II, and the Mandalore plot becomes the climax of III.