Flavour physics, supersymmetry and grand unification

A global fit to quark flavour-physics data disfavours the Standard Model with 3.6 standard deviations and points towards new CP-violating physics in meson-antimeson mixing amplitudes. Tevatron data call for a new Bs-Bs-bar mixing phase and new physics in Bd-Bd-bar mixing alleviates the tension on the unitarity triangle driven by B(B-> tau nu). In supersymmetric GUT models the large atmospheric neutrino mixing angle can influence b -> s transitions. I present the results of a recent analysis in an SO(10) GUT model which accomodates the large Bs-Bs-bar mixing phase while simultaneously obeying all other experimental constraints.