(I posted this over at the Necromancer Games boards, but I am posting it here in case anyone might be interested.)
I think True20 would work fine with the Wilderlands as far as the magic system goes. There is *some* powerful magic in the Wilderlands, but its nowhere near as commonplace as in other D&D settings. True20 could easily handle a lower-powered style of magic. There are some here who run Wilderlands using the Conan d20 and/or Iron Heroes rules, which are both sparse as far as magic is concerned.
There are a lot of non-human races in the Wilderlands, though, and I think that is part of the attraction. In some of the larger cities, even trolls and ogres rub elbows with everyday citizens in the marketplaces. Of course, as the narrator, you could easily ignore the multitude of races and have a higher human population as it suits you.