I'm thinking with a few more cores even at the same spec, and another couple GBs of RAM, I could truly replace most of my desktop computer needs with such a Pi. SATA for bonus points, but I can live with only USB HDs. Right now if I launch Chromium, for example, open a bunch of tabs, I quickly get into trouble with slowness, and crashing.
Maybe as a Pi Pro adjunct to the current Pi? Still cheap and as moddable as can be, but maybe $20 more for the above?
Perhaps three lines of Pi computers: Current Zero for minimal computing power needs, standard Pi (current Pi 3) that's great for almost any project needing a wee bit more power, and a Pi Pro for the cheapest possible fully useful desktop that still has all the rest of what makes Pis so fun and useful.