For me, I don't need more neutral or good anything. I'd rather see more epic, bad guy minions. Medium or large size, so I don't need an absurd space for the combats.
Anything in particular? Epic minions seems a bit like an oxymoron to me!
FYI, I see this as an issue in general with epic play. It isn't epic it you are still fighting minions IMO, but that is kinda how lvl 1-20 are set up. And I imagine it gets boring always fighting demon lords or arch devils. That is another reason I just added a bunch of "epic minions" from the Epic Level Handbook (they are not stated yet). One thing I am thinking of adding are swarms, such as:
Demon Horde (Different CR/stat block for a horde of balors vs horde of hezrou)
Flight of Dragons