I think the ICE engine will eventually die when we reach the stage where we can efficiently generate electricity. At the moment I firmly believe electric cars are a total cod, yes they are warranted in large cities to reduce smog, pollutants etc. but its not fooling anyone on how that power is generated. Coal primarily (or worse turf in our case!), wind is great but the fact a generator has to be kept on standby (running not generating electricity) makes it seem a bit daft and wasteful. Gas powered turbines can circumvent this due to quick starting time (Germany is rolling out loads) but until we get to terms with nuclear power, I think half of this is an exercise in stupidity. For the consumer yes it's great due to tax reliefs, but from an environmental impact point of view it makes little difference.
As Dergside mentioned one of the primary causes of greenhouse gases is methane from agriculture. Maybe we should go vegan and drive V8s :P