  Semileptonic $B$ meson decays into the four lightest excited charmed meson
states ($D_0^*$, $D_1^*$, $D_1$, and $D_2^*$) and their counterparts with $s$
quarks are investigated, including the full lepton mass dependence. We derive
the standard model predictions for the differential branching fractions, as
well as predictions for the ratios of the semi-tauonic and light lepton
semileptonic branching fractions. These can be systematically improved using
future measurements of the total or differential semileptonic rates to $e$ and
$\mu$, as well as the two-body hadronic branching fractions with a pion,
related by factorization to the semileptonic rate at maximal recoil. To
illustrate the different sensitivities to new physics, we explore the
dependence of the ratio of semi-tauonic and light-lepton branching fractions on
the type-II and type-III two-Higgs-doublet model parameters, $\tan\beta$ and
$m_{H}^\pm$, for all four states.
