  We examine the B -> D* form factor at zero recoil using a continuum QCD
approach rooted in the heavy quark sum rules framework. A refined evaluation of
the radiative corrections as well as the most recent estimates of higher order
power terms together with more careful continuum calculation are included. An
upper bound on the form factor of F(1)< 0.93 is derived, based on just the
positivity of inelastic contributions. A model-independent estimate of the
inelastic contributions shows they are quite significant, lowering the form
factor by about 6% or more. This results in an unbiased estimate F(1) \approx
0.86 with about three percent uncertainty in the central value.
