It's not really 500 damage. It's 12d8 plus maybe 20 from power attack and maybe another 20 from strength, plus, say, 6d6 damage and 1 con damage from gauntlets. Against a 40HD enemy, that's an average of 1350 damage per round, and that's not particularly optimized for level 30.
I see your point, that even 1350 damage per round may not be much in a level 30 encounter, but in a low-wealth, non-super-optimized campaign like the one I play in, it might still be viable. Also, it can come with tremendous AC, saves and HP, which the pure casters will have trouble matching. As non-spellcasters go, it seems like a wild shape build isn't a horrible epic option.
Anyway, I think what people here are saying is, I'd better make sure to have full spellcasting, even if it makes my wild shape less spectacular.
So how about this option:
Druid17 to get full spellcasting and access to epic spells, then play with Wild Shape classes, monk or whatever. Caster level will suffer a lot, but if I focus on buffs and no-SR spells, I should be okay. Or am I wrong?