Much the same as fracking perhaps. Not new in general. But the technique, coupled with directional drilling among other things... vastly improved.
The difference is subtle, but based on the resource. "Shale oil" is oil, already formed, trapped in shale and associated rock with very fine porosity, but with its origins in the shale layer. The finely porous rock associated with or adjacent to the shale is the stratum where the oil is located, or in fractures in the shale, and has the lions share of the pore spaces where the oil has accumulated Fraccing joins the otherwise isolated pore spaces in that shale and lets the oil out, often at depths of 8-10000 ft below the surface.
Oil shale is a little different, in that the oil is still forming and dispersed throughout the shale. The application of heat will finish the process of cooking the oil out that would otherwise be accomplished by the pressure and increased heat of deeper burial, depending on heat flow through the crust. Often oil shale is at or near the surface, as in the case of the Green River Shale, in Western Colorado and Wyoming. The shallow depth of the oil shales prevents fraccing techniques from being used, but horizontal drilling could be, given the right situation, and provided there was an acceptable way to heat the rock and produce the oil in/from it.
Considering the state of environmental extremism in this country, I have little faith that any such project, even if approved and permitted, will be allowed to continue to fruition without some major social changes.