I do have a character whom I have run since the mid 1980s who would qualify as an epic level character. Essentially, everything he has was earned through (if I may quote Churchill) "blood, sweat, toil, and tears." He has gone places no mortal was meant to go, faced horrors of Lovecraftian proportions, and buried many of his dearest friends. So, Oracular Vision, in what ways is this character a munchkin?
To me, a munchkin is a character that has power which is unearned. The word munchkin does get thrown out a lot around here. An epic level hero to me is someone who has achieved greatness through hard work, cunning, and perserverance. A munchkin (and I know some people who hate the word) is a character that has achieved great power by an overly generous DM.
There are many styles of play. I think if a character has an interesting story, it should not be stopped by an arbitrary level limit. (Hercules, Gilagamesh, Cu Chulainn, and Sigurd could well be considered epic level heroes from mythology.)
I have not picked up the book yet, but I will withhold my judgement until I do so.