There's a video interview on PC Perspective talking with id Software technical director John Carmack about the GPU race, Intel graphics, ray tracing, voxels, and other suitably techie topics. Due to popular demand (and threats), they have also subsequently posted a transcript of the interview, since, after all, reading is fundamental. The recently released Unlimited Detail Real-Time Rendering Technology Preview Video has attracted so much interest and criticism, his expansive answer on the topic is of particular interest at the moment, and interestingly he seems more skeptical about the actual value of "infinitive detail" than of the Voxel technology underlying the controversial video, saying: "in may ways it sounds awesomely cool: 'infinite detail,' but if we look at all of the trends that we’ve been doing and Rage epitomizes in many ways, procedurally generated detail is usually not what you want. This has been an argument going back decades: 'now is the year of procedurally generated textures and geometry.' We’ve heard that for a decade and it never has come true. What has won is being able to manage the real data that we want." He also says he now believes ray tracing is more likely to eventually win out over voxels anyway, and here's the portion with his take on this:

I’ve revisited voxels at least a half dozen times in my career, and they’ve never quite won. I am confident in saying now that ray tracing of some form will eventually win because there are too many things that we’ve suffered with rasterization for, especially for shadows and environment mapping. We live with hacks that ray tracing can let us do much better. For years I was thinking that traditional analytical ray tracing intersecting with an analytic primitive couldn’t possibly be the right solution, and it would have to be something like voxels or metaballs or something. I’m less certain of that now because the analytic tracing is closer than I thought it would be. I think it’s an interesting battle between potentially ray tracing into dense polygonal geometry versus ray tracing into voxels and things like that. The appeal of voxels, like bitmaps, [is that] a lot of things can be done with filtering operations. You can stream more things in and there is still very definitely appeals about that. You start to look at them as little light field transformers rather than hard surfaces that you bounce things off of. I still wouldn’t say that the smart money is on voxels because lots of smart people have been trying it for a long time. It’s possible now with our current, modern generation graphics cards to do incredible full screen voxel rendering into hyper-detailed environments, and especially as we look towards the next generation I’m sure some people would take a stab at it. I think it’s less likely to be something that is a corner stone of a top-of-the-line triple A title. It’s in the mix but not a forgone conclusion right now.