  We investigate the recent CDF measurement of the Br(B_s --> mu+mu-) which
shows excess over the Standard Model. We consider minimal supergravity
motivated models (mSUGRA)/CMSSM and grand unified models, SU(5) and SO(10). In
the grand unified models, the neutrino mixings provide an additional source of
squark flavor violation through the quark-lepton unification. In the context of
minimal SU(5) model, we find that the new CDF measurement has imposed a lower
bound on the branching ratio of tau --> mu gamma for a large CP phase in the
B_s-bar B_s mixing. Recall that there have been indication for a large CP phase
in B_s mixing from B_s --> J/psi phi (Tevatron and LHCb) and dimuon asymmetry
(D0). We also predict Br(tau --> mu eta) for the possible range of values of
Br(tau --> mu gamma).
