  We present the status of our updated D- and B-meson decay-constant analysis,
based on the MILC $N_f = 2+1$ asqtad gauge ensembles. Heavy quarks are
incorporated using the Wilson clover action with the Fermilab interpretation.
This analysis includes ensembles at five lattice spacings from a $\approx$
0.045 to 0.15 fm, and light sea-quark masses down to 1/20th of the
strange-quark mass. Projected error budgets for ratios of decay constants, in
particular between bottom- and charm-meson decay constants, are presented.
