When will we see a market place that includes Plug-in Hybrid Electric Vehicles

This is a tough question. There are so many variables involved here, not the least of which are public demand for these vehicles, manufacturer inclination to produce them, etc. So far, the hybrids being produced have been pretty much a losing proposition for many manufacturers. They produce them but typically break even or lose money on each one sold. This is why great cars, like the Honda Insight, don't last long in the marketplace. Plus I think that the mfgs. are trying to introduce hybrids slowly, and keeping the gas/electric setup because they are trying to acclimate the public to the technology without the stigma of a "plug-in" car, which was always the old argument against electric cars -- "oh, you'll only be able to go 50 miles and then have to charge them for 8 hours..." That said, I believe the Smart Car scheduled for release in the next year or two has a completely electric plug-in model available. Right now, the gas/electric is an excellent choice because they can use the gas engine or the electric motor as needed, and convert kinetic energy normally lost through braking to charge the battery as well. One of the other big hurdles to this is battery technology. I have heard it said that most batteries in the hybrid cars need to be replaced at or near 100k miles, at a cost of several thousand dollars. I would think this problem would be endemic to the plug-ins, too.