Yep, the only thing 8.1 is missing is a cell radio - it and hardware that runs it well are more than capable of conventional cell phone duty. All the other pieces are in place. I'm not ready to suggest the miniaturization of the hardware or the battery technology is ready to cram that stuff into a cell-phone sized (~4") package, but it very well could be. If it's not, I'd say with a fair degree of certainty we are not far off.