Simply having an x86 chip would not be enough. I have forgotten the specifics but I remember some debate about getting Windows to run on a SoC and it was not something that would be easy to do, the boot process is completely different.
Installing x86 Linux systems like Ubuntu would be pretty easy because it doesn't care much about the boot process and what it does care about we have the source for and can fix.
So right from the start your idea that "if it was just X86 it would do everything I want and more" is flawed.
That being said, on your list: Diablo 2 runs on the Pandora with some frame skipping, arguably well enough to actually play and there's every reason to believe the Pyra will be able to close the gap; Ditto for Morrowind, and if not the actual game in emulation then OpenMW should be a good second choice; can't speak for disciples, mtg, or halo, but the Pandora already has many flavours of Doom that can run all kinds of different mods so you won't be lacking there. Plus all the emulators that already exist and will continue to be expanded upon. And all the rest except the webcam are already built into it of course.
So the question still stands: what is it that you want it to do that you think requires an x86 processor