The new 2010 Toyota Prius will be unveiled at the Detroit Auto Show
next January along with a Lexus badged derivative. When the third (or fourth depending on whether you count the original U.S. model as a second gen) Prius debuts it will retain the current hybrid
setup with a nickel metal hydride battery pack. The gas engine is expected to be updated and grow from the current 1.5L to 1.6L. The five door hatchback body style is also expected to grow a bit although the fuel economy
is not expected to suffer. If the rendering produced by Car and Driver is anything to go by, not much of the new Prius design will come from the Hybrid-X concept
that Toyota showed at the 2007 Geneva Motor Show. In 2010, Toyota will start building a few hundred Priuses with lithium ion batteries and plug-in capability for commercial and government fleet testing. A high volume retail version won't appear until 2011-12.
[Source: Car and Driver