BUT, my point is: I don't think ALL legendary items/artifacts should be related to quests. In Oblivion, they basically were. I honestly don't remember a really great artifact that I got from somewhere other than a quest.
In Morrowind, things were different. There, some of the legendary items/artifacts were related to quests (especially Mages Guild and Temple quests and of course the main quest ) but far from all were. Many of the artifacts in Morrowind were something you stumbled upon when you randomly searched dungeons, heard a mysterious rumour, or did some completely other quest that related to that specific dungeon and not to that specific artifact. I think this was really good. A very nice balance, which I hope to see in Skyrim too.
In addition, I think legendary items/artifacts in Skyrim should be stronger/better, like how they were in Morrowind. They should also be hard to get... and be well hidden. I remember when I first discovered the artifact Eleidon's Ward.
It was high up near the ceiling in a long forgotten, well protected, well locked daedric room in a cave. I mean, that's simply awesome. It's things like this that makes it feel really worth searching everywhere. You never knew if you were about to find another legendary item.
Do you agree?