  Armed with the information on the form factor $\fdpi(0)$ inferred from recent
CLEO measurements of SU(3)-breaking effects in charmed meson decays, we have
studied the form factor $\fbpi$. In the heavy quark limit, $\fbpi(q^2)$ is
related to $\fdpi(q^2)$ in the kinematic region close to zero recoil. Assuming
pole dominance for its $q^2$ dependence, $\fbpi(0)$ is estimated to be $\approx
0.39\,.$ If the requirement of heavy quark symmetry is relaxed so that it
applies only to soft pion emissions from the heavy meson, we find that
$\fbpi(0)$ is more likely of order $0.55\sim 0.60\,.$
