  We reconsider and update the QCD light-cone sum rules for $B\to \pi$ form
factors. The gluon radiative corrections to the twist-2 and twist-3 terms in
the correlation functions are calculated. The $\bar{MS}$ $b$-quark mass is
employed, instead of the one-loop pole mass used in the previous analyses. The
light-cone sum rule for $f^+_{B\pi}(q^2)$ is fitted to the measured
$q^2$-distribution in $B\to \pi l \nu_l$, fixing the input parameters with the
largest uncertainty: the Gegenbauer moments of the pion distribution amplitude.
For the $B\to \pi$ vector form factor at zero momentum transfer we predict
$f^+_{B\pi}(0)= 0.26^{+0.04}_{-0.03}$. Combining it with the value of the
product $|V_{ub}f^+_{B\pi}(0)|$ extracted from experiment, we obtain
$|V_{ub}|=(3.5\pm 0.4\pm 0.2\pm 0.1) \times 10^{-3}$. In addition, the scalar
and penguin $B\to \pi$ form factors $f^0_{B\pi}(q^2)$ and $f^T_{B\pi}(q^2)$ are
calculated.
