Adrian Kent at Cambridge et-al appear to be able to derive the rules of orthodox quantum theory. However, orthodox quantum theory is only a limiting case of a more general theory. This is obvious in Bohm's interpretation and has been developed in some detail by Antony Valentini now at Clemson University. The idea of entanglement signaling is that we no longer need the classical signal key to decode the message from the sender at the receiver. One key assumption in no-signaling propositions is the indistinguishablity of non-orthogonal states. At least one Chinese physicist thinks otherwise: "Tian-Hai Zeng
Department of Physics, Beijing Institute of Technology, Beijing 100081, China
"I design a simple way of distinguishing non-orthogonal quantum states with perfect reliability using only quantum CNOT gates in one condition. In this way, we can implement pure quantum communication in directly sending classical information, Ekert’s quantum cryptography and quantum teleportation without the help of classical communications channel." Tian-Hai Zeng
Department of Physics, Beijing Institute of Technology, Beijing 100081, China"
http://arxiv.org/pdf/quant-ph/0509093.pdf
I have proposed another way using entangled non-orthogonal Glauber states produced by lasers. In effect, the Glauber states show the measurability of non-Hermitian photon destruction operators when there is spontaneous symmetry breaking. I presented this at the SLAC APS meeting 11-1-11 and will again at the Boston APS meeting section D30 Monday, Feb 27, 2012.
see http://spectrum.ieee.org/tech-talk/computing/hardware/why-im-wagering-100000-on-quantum-computing