  Motivated by the energetic advantage of achieving coherent enhancement of
effective spin-dependent interactions through approximate nesting, we propose
specific forms of spin ordering, whose form varies over the Fermi surface, for
the cuprate superconductors. Competing "spin-orbit" orderings involving order
parameters in spatial $d_{x^2-y^2}$ and $d_{xy}$ waves at commensurate and
incommensurate wavevectors, phase separated in momentum space, support behavior
suggestive of observed phenomena. The $d_{xy}$ spin-orbit fluctuation induces
an effective interaction that favors $d_{x^2-y^2}$-wave pairing, as required
for the observed superconductivity. Anisotropic spin susceptibility is a
crucial prediction of our mechanism.
