When I played Oblivion years ago, I got bored quickly, but I think it was because I was too focused on tackling the main quest line. Knowledge of how the level scaling worked led me to having an overpowered character, and closing the Oblivion gates was repetitive and mostly easy because (IIRC) I could just run past most of the threats.

I heard later that there is a lot of interesting stuff to discover if you ignore the gates. I would like to try that some time, and it would be pretty cool to do it with an upgraded game engine & environment. Here's hoping this project gets the volunteers it needs.