Not if thorium reactors become the norm, and coal/oil/gas isn't going to get any cheaper. Besides, your contention that nuclear is the most expensive - you used somewhat more exagerated terms than that - is seemingly false if one takes the time to indulge in a small amount of research and look at a few facts and figures.
http://www.pbworld.com/pdfs/regional...ange_costs.pdf
Oil especially seems to be largely in the hands of nations who would quite happily take actions to bump up the price when they feel like it, they have done in the past. There may be untapped sources of black gold but they're going to have to be in quantities as yet undreamt of to keep the world in the lifestyle to which it has become acostomed to for any length of time. And of course the majority of places in the world best placed to collect solar energy are controlled by 'those of a certain disposition'. USA may be ok re. solar if they build a swathe of them across the S. Western States, but Northern Europe won't be.