Hurkyl,
I'm in agreement with what you're saying. But my motivation for grinding this into the ground gets back, of course, to my attempting to understand density matrices as the foundation for QM. Here's the problem from the DM point of view.
If one characterizes fermion states by \psi(r_1,r_2) = -\psi(r_2,r_1), then the statement that no two fermions exist in the same state follows in that one has that \psi(r,r) = 0. The problem for the density operator formalism is that this way of characterizing fermion states is written in spinor formalism, not density matrix formalism.
If I could instead characterize fermion states by "no two fermions can occupy the same state", then the definition is written in terms of quantum states, rather than spinors, and one can immediately apply it to the density matrix / density operator formalism.
The problem is that I don't see how to get from "no two fermions can occupy the same state" to \psi(r_1,r_2) = -\psi(r_2,r_1) without making a bunch of other assumptions. One of those assumptions would be linear superposition, which is already iffy in the density operator formalism since linear superposition is normally applied to spinors instead of density matrices. Another assumption is that the wave function must treat all identical particles equivalently. This assumption, CAN be written into the density matrix formalism.
I do think that there is a way to elegantly obtain the PEP / fermion wave function restriction completely inside the density operator formalism, and that is by assuming that the PEP follows as a force of constraint. (And when spin is generalized to bigger Clifford algebras, the constraint force implied could be used to make preons clump together.) To do it, we enforce the restriction by assigning a very high potential energy to violations of the PEP. This turns out to be very natural for fermions described as density operators.
The difference between bosons and fermions then becomes whether or not they have the charge for the force associated with that potential energy. Fermions have the charge and are forced away from each other. Bosons don't. By the way, I've seen a paper claiming that the quantum zeno effect, when applied to bosons, causes them to act like fermions, without the quantum zeno effect:
http://arxiv.org/abs/quant-ph/0408097
Here are some interesting papers. They demonstrate that the pros get into fights about this in the peer reviewed literature that have to do with how the PEP should be written:
Phys. Rev. A 67, 042102 (2003)
http://www.arxiv.org/abs/quant-ph/0207017
http://www.arxiv.org/abs/quant-ph/0304088
Phys. Rev. A 68, 046102 (2003)
http://www.arxiv.org/abs/quant-ph/0402118