I currently have 80K on my '05 package 6 that is truly loaded with stuff including the California Carpool access stickers. But I am looking forward to the next model Prius when it comes out. IF California authorizes another "batch" of the Carpool stickers for release, I will sell my Prius and buy the new model. BUT, if they do not release more stickers, I will likely just keep my present Prius as the Carpool access is good until 2011. I am really hoping CA releases more stickers next year and Toyota releases the new model Prius- then I would be quite pleased. Oh well...just dreaming.
I'm not sure either is going to happen anytime soon, its looking like 2010/2011 for either of those. Sorry, I'm not my touch right now and don't have anything to cite right now but if you do a little searching on here you can find more info on them.