  The calculation of partial decay rates in B --> X_u l nu decays at
next-to-next-to-leading order (NNLO) in alpha_s and to leading order in 1/m_b
is described. New results for the hard function are combined with known results
for the jet function and shape-function moments in a numerical analysis which
explores the impact of the NNLO corrections on partial decay rates and the
determination of |V_{ub}|.
