In the Elder Scrolls games you're always the hero, whether you want to be or not.Sure, you start Morrowind, Oblivion, and Skyrim as the chosen one, but you're free to dick around. You can complete the main quest at your leisure (though Oblivion suffers a bit in this regard), or even choose to completely ignore it in favor of better written plot lines.
At least for myself, the main draw of TES games has never been the main quest. Hell, in Oblivion, I saw the main quest as being more bothersome than anything else, and, although better than its predecessor, Skyrim's main quest wasn't really that great either. Instead, the main draw has been the large, expansive world to explore. The most memorable moments were when I found something interesting. I still remember stumbling across Ibar-Dad in Morrowind.
But the thing that has me most skeptical is that they're making the hero part of the game single player. Of course, as I've said before, I'm not a big fan of the idea of heroics being built into an MMO, but making that aspect of the game a solo experience might be the right choice. By getting their big damn hero quota out of the way as a solo experience, the developers will be able to focus on making the actual MMO part of the game better. That or they'll overly focus on the solo experience, leaving the rest of the game shallow and useless.
In the end, I'm hopeful for the game, but it's hard after seeing so many other people try to make MMOs and fail.