While there are ways to counter the casters using the drawbacks in the game, I think throwing the monkey wrench every day will just make the player grumpy. What should just happen is giving the non-casters some shiny stuff, too. We all know that the balance the game designers had in mind doesn't work - being able to do something all the time vs. in slots is worthless if you either have enough slots all the time, or if the effects you get from slots are so much stronger, that it really doesn't matter. That and cheating the system via retreating to the safe-house. Mind you, in campaigns where you can't retreat, can hardly rest, etc, magic is suddenly a lot weaker. There was that super-solo-dungeon that went around a while, where it was quite apparent that casters weren't able to beat it - simply because they had to do too much before resting. But that's still a rare example.
So, basically, on a per-encounter scale, non-casters need stuff to do. And I think the ToB is almost there, but not quite. Incarnum is a kind of magic, but has a different feel, it's also almost there, just because you can also kick major ass with it. A combination of the two still can't change the world, but at least can kick major ass, which might be enough to make those people happy who don't want to cast spells.
I would say give that a prestige class to combine the two would be rather nice. It will still not be able to break above Tier 3.