For some time now the third generation Toyota Prius was expected to debut in the fall of 2008 carrying a lithium ion battery pack and and very possibly plug-in capability. In the past week it has been reported that neither the lithium energy storage or the plug-in capability would be there and now it looks the timeline has slipped as well.
Of course, since Toyota never officially announced a launch date they are refusing to call the slip to a spring 2009 debut a program slip or even acknowledge the new or old date. By the time the new Prius hits the market there will be several new competitors available including the Ford Fusion/ Mercury Milan hybrids and the plug-in version of the two-mode Saturn Vue is due that same year.
It looks like Toyota's decision to stick with their local supplier might have come back to haunt them. Panasonic currently supplies the NiMH hydride batteries that Toyota uses and they have been focusing on LiNiCoAlO2 cathodes which are considered to be the least thermally stable of the currently available lithium chemistries. Other companies like A123 use materials such as doped iron phosphate and other materials that have better thermal stability. At this stage of the program Toyota might actually better off going to a new source for lithium batteries rather than reverting to NiMH.