Recent CP asymmetry measurements in tree-dominated processes,, and in penguin-dominated decays, B → π 0 KS, η ′ KS, φKS, are interpreted in the framework of the KobayashiMaskawa (KM) mechanism of CP violation. The KM phase emerges as the dominant source of CP violation in treedominated decays, which are beginning to constrain the unitarity triangle beyond other constraints. Improving precision of CP asymmetry measurements in penguin-dominated decays may indicate the need for new physics.