I don't understadn the "need" for an epic system at all. If WotC had been smart, they could have made classes with 100 levels (what i am going for here is "100%" sorta idea; i hope people get that). But that would be too complicated, i suppose. Oh well, her's to hoping for it.
The point is, the Epic Level Handbook is sorta an afterthought - an oversomplicated afterthought. Cus now all those feats needed to be upped for an eipc version, new rules needed to be incoorperated, etc etc.
What i would love to see is a 100 level character build that is smooth and flows well. With it, there would be obvious transistions of power - guys like Alexander the Great, Heracules, Charles Martel, Shakespear and other "great ones" would be over level 50, probably by a long shot for many, commoners levels 1-5 or 10 and PC's falling somewhere in between. Exp needed for levels could probably be dropped a bit, but not by too much . . . so as to maintain balance in the world (i.e. surviving an orc raid wouldn't give you a level).
I know i am being very general here, but i have a few problems with the d20 system. I guess its a flaw of the system, since WotC was trying to stay as close to TSR traditions without killing off too many sacred cows (can anyone say "paladin?" - the most obvious of the core classes that should be a PrC). Same with 20 level progression - like i said, 100 level progression would be so much better, and it could truely cronical the PC's ascension into truely epic and mighty individuals. That is what i would like to see.
That probably won't help you one nanobyte, but i figured i'd chime in my opinion on this. Ugh, ever do i find myself trying to think of ways to improve things, but always afraid to tamper with things too much, lest i completely drive myslef or my players nuts. Maybe, in the future, i'll be able to write up/publish something, but for now, i'll put up with the d20 system, warts and all. *sigh*