Elder Scrolls is the perfect example of what gaming, and in particular, RPGs can be. The multiplayer concept would do nothing but destroy the potential for growth in the story. But if Bethesda feels the need to try and gain from the online gaming boom, might I suggest some sort of multiplayer arena perhaps. Instead of arena battles being against NPCs, they could be fought against a similarly leveled player, thus maintaining the integrity of the series, but conceding to the CoD trend.
And while the perk mechanic worked great for Fallout, I would rather not see it make it's way into Tamriel. Fallout may have tried to combine shooter and rpg elements, but in the end, it is still a shooter. Elder Scrolls is a first person action RPG, and should function as such.
Might I also suggest making the older games available for purchase online, or through XboxLive Marketplace.
I know people hate thinking TES multiplayer, but an arena idea might be cool. Have you played Dark Messiah: Might and Magic? It has a multiplayer option which, while not that great imo because the classes just weren't good for MP but that could jsut be because im terrible at PvP, you start out level one each game you join, and you get up put skills in and do stuff like CTF, headquarters, and big battles, one of them had 128 people able to join to battle it out. Now this would be hard for TES because you level up differently and its a much much bigger game than Dark Messiah, however its possible they could do it. But even though it would be cool, i think they should make the single player game first and devote all their time to that, then maybe add the multiplayer later, as an expansion or something.