Updated Analysis of Some Two-Body Charmless B Decays

New data from the BaBar, Belle, and CLEO Collaborations on B decays to two-body charmless final states are analyzed, with the following consequences: (1) The penguin amplitude which dominates the decay $B^+ \to \pi^+ K^{*0}$ has a magnitude similar to that dominating $B^+ \to \pi^+ K^0$. (2) The decay $B^+ \to \pi^+ \eta$, a good candidate for observing direct CP violation, should be detectable at present levels of sensitivity. (3) The decays $B^+ \to \eta' K^+$ and $B^+ \to \eta K^{*+}$ are sufficiently similar in rate to the corresponding decays $B^0 \to \eta' K^0$ and $B^0 \to \eta K^{*0}$, respectively, that one cannot yet infer the need for ``tree'' amplitudes $t'$ contributing to the $B^+$ but not the $B^0$ decays. Statistical requirements for observing this and other examples of tree-penguin interference are given. (4) Whereas the $B^+ \to \eta' K^+$ and $B^0 \to \eta' K^0$ rates cannot be accounted for by the penguin amplitude $p'$ alone but require an additional flavor-singlet penguin contribution $s'$, no such flavor-singlet penguin contribution is yet called for in the decays $B^+ \to \eta K^{*+}$ or $B^0 \to \eta K^{*0}$. Predictions for the rates for $B^+ \to \eta' K^{*+}$ and $B^0 \to \eta' K^{*0}$ are given which would allow one to gauge the importance of these flavor-singlet penguin amplitudes.