Toyota's plan to add hybrid versions of all its models over the next decade is continuing over the next several years with at least two more Lexus models joining the Rav4 in adding batteries and electric drive. When the next-generation IS debuts in a couple of years, it should get a rear-wheel drive hybrid variant as well as a new, higher-performance sports car version.
Interestingly, Autocar is also reporting that Lexus will build a new SC with hybrid drive to replace the current slow-selling model. The current SC will cease production in June of this year but the new model won't arrive until 2014. That model is expected to use a 5.0-liter V8 with its hybrid, just like the current LS600h.
On the Toyota brand side of the house, the Rav4 will go hybrid with its next redesign two years from now. Unlike the V6 hybrid in the Highlander, Toyota will probably use a four-cylinder package based on the Camry for the Rav4.