In a nutshell, Morrowind is full of quests with characters left... hanging. You know, they say their off to find their fortune, will meet you back at the Guildhall... but they just don't move. Standing out in the wilderness months later, saying they'll be off 'anytime now.'
Problem is, all I can think of is Caius, who says hes about to ship back to the Imperial City, but is still hanging around long after you've killed Dagoth Ur and saved the land. He doesn't even say thankyou!
I know there are a million and one others, I was hoping you guys could throw some suggestions my way? It can be obvious ones like npcs that need to be disable or moved to where they say they're going to be, or ideas you think might be more exciting - seeing those travellers you saved on the road at an Inn the other side of Vvardenfell a week later, for instance. Or maybe slaves you've freed moved to the Argonian mission. Whatever springs to mind!