I am looking forward to this book more than any other since 3rd Edition was announced. I will enjoy the options more than anything. Will this book factor into my weekly game? Maybe. I like the option to play whatever story I want.
I enjoy role playing for the ability to play any story I can imagine. In D&D, this is a fantasy, sword and sorcery campaign. Right now, however, SOME stories set in this settings can be told, but not the very powerful, legendary adventures. The ones where the powerful adventurers save the world from the angry gods, or when the overwhelmingly powerful dragon threatens to remake the world in his image and the servants of the gods are called upon to make things right. Right now, there are no good rules to play these games.
Are these games less or more fun than low level ones? I'd say neither. They are different stories, the same way that a Star Wars RPG is different than a D&D game. The only difference is that the Epic Level Book can be used to extend a normal D&D game to higher levels if you wish, instead of starting a new game.
Unlike some others here, I don't play RPGs for characters, I play them for story. To me being the first level fighter who picks up a sword for the first time and has grand hopes is just as much fun as playing the legendary warrior who has saved the world many times in the past and has yet to meet his equal. It is a challenge to constantly have new character types thrust upon me. But, more importantly, is the story I get to go through. I always have great anticipation each week, waiting to see what interesting and fun challenges I will have to defeat this week. Some people may enjoy role playing balls and political functions, knowing that they are expanding their characters. I'm not happy unless I'm saving peoples lives and defeating evil.
Majoru Oakheart