What would be the impact of a 'fusion economy', assuming realistic evolution of the technology for the purposes of commercialisation? (i.e. I'm assuming "Mr Fusion" powerplants on top of one's DeLorean aren't ever going to be practically feasible).

What would such a world look like? Does it promote world peace; through greater energy security for nations, would less reliance on fossil fuels for baseload electricity generation have a significant impact on price of air travel/sea cargo?