Theoretically, yes. If you are capable of effectively decompiling the software in order to make the determination of what constitutes a node. Realistically, since an actual node is coded directly into the core, no. Not unless a shader SDK is released.

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)