Toyota Hybrid Van - more info.

Toyota actually has two platforms for the minivans, one that is based on the Camry that is used for the Sienna that is sold in the US, and one called the Previa which is no longer sold in the US. The Previa was sold in the US until 1997 when it was replaced by the Sienna. The idea being American vehicle buyers like a larger, more powerful vehicle which the Sienna definitely is. The sad thing is the Previa has a hybrid version, and the Sienna does not yet. Rumours are from 2008 Fall to 2010 for a Sienna hybrid. My guess is battery capacity as Toyota changes over from Nickel Hydride to Lithium is impacting the date.