From what I gathered from John Carmack, ray tracing is done much more efficiently with voxels than with triangles, so hopefully this will push game engine companies to incorporate voxels sooner into their engines, too.
There are a lot of very nice mathematical properties of triangles, and the trend towards graphical fidelity has really only served to balloon budgets in the gaming space. We don't need voxels, and honestly neither do we need ray tracing.
It's not even new tech--games going back to Outcast, some Build engine games, Novalogic stuff, and so on have used voxels. Ray tracing has been used in a handful of nifty tech demos, but otherwise nobody cares.
Ray tracing and voxel tech is of marginal utility for games, and things have moved on--it'd be like switching the US construction industry over to metric; too late to make a difference and too minor to matter.
EDIT: In spite of all this, voxel cone tracing looks sexy as hell though.
There are voxel engines now that store world data using voxels while what the player actually sees is polygons based on that voxel data.
I'm reminded of one guy's side project[1] that accomplishes exactly that.
[1]http://procworld.blogspot.com/2012/12/videos-of-caves-and-bu...
Hence, it's not a realtime "voxel engine" as far as visual rendering goes.
Pixar probably didn't need to do a voxel -> triangle transformation to their data set if they were using voxels, but any real-time renderer does.
Also don't forget voxels take an order of magnitude more memory. Voxels are hyped because of minecraft, and in terms of acceleration they're really not trivial at all.
I remember some nifty demo with voxels though. But honestly wait for the real-time graphics API mess to smooth up a little before going voxels. You can still do a big lot with triangles.