The duplication glitch is there because to me it also represents infinite quest rewards.
I am strongly in favor of "game exploits" being present in Skyrim, because it shows a certain amount of inventiveness on the part of the player. In Morrowind, for example, having a 2-point constant effect restore health enchantment didn't help you complete quests that didn't involve combat, while giving you an advantage in combat unparalleled by the NPCs. Weakness to magic was something the player could do in Oblivion to boost their own magical power, and it was defensive as well as offensive, which made magic the force to be reckoned with that it was. 100% Chameleon makes sense after using invisibility for the first time, and 100% reflect spell/damage gives the user an advantage in combat. None of these achievements are immediately obvious, or in fact easy to create, and seeing as enchanting appears to be a skill again it would be nice if we can develop our character into someone worthy of saving the world from a god.
My main argument in favor of these is that they take effort to achieve, even for those who heard about rather than discovered them. After all, life isn't about the destination, but rather the journey, and if someone wants to role play an overbalanced character then shouldn't the developers let them, but restrict their journey to becoming overbalanced? You could give characters the ability to make weak enchantments at low enchanting skill levels and stronger enchantment at higher levels, both in terms of magnitude and spell-effect
I also strongly believe that quests in Skyrim will be a reminiscent of Morrowind's investigative questing style, not a case of follow the quest marker until you reach your destination, with the difficult part being overcoming enemies, as this didn't work for me in Oblivion.
Enough about my opinion. What do you think?