With an announcement, not that long ago from Volvo where they are not going to produce petrol engined cars after 2018 (?), I reckon that petrol engined cars will be left behind and the hybrids will be the future... Once hybrids become the 'norm' Hydrogen engined cars will be the future.... I reckon it'll be within the next 50 years that hybrids and hydrogen engined cars will be the 'norm'...
No, Volvo announced that they're not going to DESIGN I/C engined cars after
2020. But that's pure marketing wank as they've just finished replacing their entire range with brand new designs, which includes new I/C engines. They're set for years, as their models have always had long lives. They already sell hybrids.
As always, it's infrastructure that matters: supplying large amounts of hydrogen requires lots of electricity to separate it, fully electric vehicles require a good supply of electricity to charge the batteries(which are
another problem) and fossil fuels have to be separated from the crude oil.
None of those are things you would willingly implement from scratch. I didn't include hybrids in that list as they are at best a stopgap - they are a political solution to an engineering problem, and we all know how good those are!