Speculation and energy now centers around a few semi-interesting trends, like Tablet PCs, wireless PDAs, "convergence" devices like Microsoft's HomeStation project, single-use "appliance" boxes, and PCs as "digital hubs" for the home.
Those things are fine for what they are, I suppose, but I'm still more interested in what my home-built, general-use PC will be doing for me in five or ten years. Things like Hollywood-quality real-time rendering, real and effective high-quality positional audio, high-bandwidth networking and clustering peer-to-peer funkiness, or... well, what? What's next for the PC? What will our ever-expanding computing power allow us to do that we can't do now? And how will that computing power expand? What kinds of breakthroughs could come, and what kinds of applications could they enable? Have we just lost our vision, or are we, in some substantive ways, nearing the end of this particular road?