  Recent experimental and theoretical progress regarding B --> K(*) l+ l-
decays led to improved bounds on the Wilson coefficients C_9 and C_10 of
four-fermion operators of the |Delta B|=|Delta S|=1 effective Hamiltonian. We
analyze the resulting implications on squark flavor violation in the MSSM and
obtain new constraints on flavor-changing left-right mixing in the
up-squark-sector. We find the dimensionless flavor mixing parameter
(delta^u_23)_LR, depending on the flavor-diagonal MSSM masses and couplings, to
be as low as \lesssim 0.1. This has implications for models based on radiative
flavor violation and leads to BR(B_s --> mu+ mu-) \gtrsim 1 x 10^-9. Rare top
decays t --> c gamma, t --> c g, t --> c Z have branching ratios predicted to
be below \lesssim few times 10^-8, 10^-6 and 10^-7, respectively.
