Google Maps Navigation becomes more of a threat to the traditional in-car GPS business seemingly on a daily basis, and they're taking another stab at it today with the addition of traffic re-routing capability in the Android app (which, while technically still in beta, is pretty darn solid) in both North America and Europe. Of course, Maps has had access to traffic information for a long time, so this is a natural progression -- and just as Google uses an interesting combination of sources (including phones) to cull that data, it's employing some smart schemes for re-routing that take into account both current and historical information about your route. The update's available today.