There's truth in both arguments being presented here.
Pro-Epic:
I can finally continue playing my high level character, with an officially supported system for it, that gives me all sorts of cool options and growth possibilities.
I can make villains to challenge my high level (15-20) PCs, and not require them to have an army or two to spare to last more than a round.
Those of us who have characters who have ascended to godhood can possibly still continue playing them (possibly....).
Anti-Epic:
I'm sorry. 800 hp is a bit silly. I mean, heck....what would a 120th level Barbarian look like? 1700hp? That's nuts, when you think about it. That's like surviving re-entry, falling down the gullet of the tarrasque, living through its digestive processes, coming out the back end, and going swimming through a pit of lava. I mean, really.
I really don't have much of a problem with munchkins. I don't play with them, and I don't run for them, but if they want to play in games suited to their taste, and others want to run them, then by all means go for it. The difficulty comes in hearing about people's Sorcerer48/Fighter81/Barbarian293/ Rogue65345 Half-Gold Dragon Lich Minotaur who killed all the gods in every pantheon, chained their tormented spirits up in a pit, and forces them to make booze. It's shades of 1st edition. I think it's already been mentioned, but remember the old Waldorf letter in old issues of Dragon, and the flood of response letters a few months later? *sigh*
Truthfully, I think a new term needs to be coined for these folk. 'Munchkin' is an overused term, not very specific, and too broad. I think the term 'weenie' applies a bit better, but that's just my opinion.
Anyway, the whole point is really moot. I know I'm going to enjoy the books, and will have fun using them. Others will disregard them or go hog-wild with them. Such is the nature of everything.
In the end, the only really important question is 'Are the players having fun?' If the answer is 'yes', then there's no problem.
ps. As for the issue of this stuff taking up space in books that could be used for other purposes more suited to other gaming styles....that could be said for ANY content in any of the books. Personally, I have no use for any campaign-world information, society information, discussion of the nature of magic, tactics and strategy discussion, and character background suggestions. Does this mean that they shouldn't be there, and should be replaced with more feats, rules, and spells? No. I might prefer that, but as long as there's a decent balance, I'm satisfied.