I think almost any car company can come up with a hybrid, electric, or fuel cell prototype. Actually being able to sell them at a profit is where the skill lies, and yes, this is what Toyota and Honda have done.
We have seen many compnies showing off their technology, but no one else has made it work yet. I think the size of the battery pack for the Volt is so large to make it very expensive to produce. Conventional Hybrids have much smaller battery packs, and this is why they are relatively affordable. i suspect the future beyond Petrol or Diesel hybrids will be Hydrogen fuel cells, and guess what. Honda are there already, even if its only in limited numbers.
But a large number of plug in Hybrids or Hydrogen fuel cell cars are going to put a huge strain on electrity generation which in the UK we are no where near ready for (i dont know about the rest of the world). So i think we are all going to be driving using perol or diesel in one form or another for a very long time into the future.
405 Le Mans, Monaro CV8, S2000, MKX 3.8. No more space.