I guess I should have kept reading before I finished my post above because another article I just read says that Toyota and Matsushita Electric have been working on a Li-ion battery pack to debut in the 2009 Toyota Prius. I guess a few other companies are working on the Li-ion technology for the hybrid market too including Toshiba and Hitachi electric. Sounds like we'll be seeing them arrive in the market around the 2010 timeframe.