Wulf Ratbane
Adventurer
Seems like a nice workable system.
My own tweak was to allow anyone able to make an iterative attack to instead make a Mighty Blow as a full attack action.
For each iterative attack lost, the single attack gets bonus damage equal to the base damage of the attack.
There's nothing wrong with that approach per se, but as I mentioned upthread (a few times) it will dramatically undercut the amount of damage your melee classes can dish out.
If your 2nd, 3rd, 4th iterative attacks previously included power attack, or flaming, aligned, holy, or sneak attack dice, you're losing all that damage. Adding in any amount equal to "the base weapon" means that anybody with more than +2d6 in bonus damage loses out in the bargain.
This is important because high-level monsters are designed to get hit. They don't survive contact with the PCs by making the PCs miss; they survive contact with the PCs by having an assload of hit points. If you curtail the damage of the fighting classes, combat will last longer. See various 4e "grind" threads for evidence of the unpleasant side effects. And 4e at least has the advantage of not having a lot of save or die effects; increasing the duration of combat by "just a couple of rounds" in 3e might mean "just a couple of rounds" of extra save-or-die effects coming at you.