Consideration is being given to upgrading the SuperKEKB e+e- collider with polarized electron beams, which would open a new program of precision electroweak physics at the Y(4S). These measurements include sin2 theta_W obtained via left-right asymmetry measurements of e+e- transitions to pairs of electrons, muons, taus, charm and b-quarks. The precision obtainable at SuperKEKB will match that of the LEP/SLC world average but at the centre-of-mass energy of 10.58GeV, thereby probing the neutral current couplings with unprecedented precision at a new energy scale sensitive to the running of the couplings. World average measurements of the individual neutral current vector coupling constants to b- and c-quarks and muons in particular will be substantially improved and the residual 3sigma discrepancy between the SLC ALR measurements and LEP AFBb measurements will be addressed. This paper will include a discussion of the necessary upgrades to SuperKEKB. This program opens an exciting new window in searches for physics beyond the standard model.