Battery life has never
Battery life has never worried me. Back in 2008, I visited Southern California Edison who had just finished lab test with Johnson Saft lithium ion and found they could handle 200,000 without noticeable degradation. That put any fears I had to rest.
I don't think too many people drive past 150K, simply because the vast majority of people don't know how to maintain a car and most of the cars on the road are not that great a quality.
The way I see PHEVs is that they are the perfect stepping stone before we get to full EVs. People got bombarded with that idiotic range anxiety (thanks GM!) and that slowed down enthusiasm, probably not adoption. Although we have EVs that can handle 240 and now 260 miles, the price will come down even more n the next few years.
I think it's a question on intelligent balance. We need to see gasoline cars that cut down on emissions and consumption, as well as hybrids, plug-in hybrids and electrics. As we move into the years, the goal is to go fully electric, at least that's what I'm getting from many carmakers. And it makes sense.
The next step might not be so much battery chemistry but tweaking what we already have. I've written something on it on the Examiner. Better management, better cooling and better written software will help us squeeze an extra 70 mile from what we have today. We're getting there.