I think fashion certainly changes the connotation of the term. Connatation is simply what a term commonly brings to mind when people hear it. If the word "geek" ceases to bring derogatory images to mind when someone hears it, it ceases to be pejorative. But I don't mean fashion as in six months from now the term will become pejorative again. I mean that the world, led by the U.S. and a couple others, is going through a paradigm shift into the "computer age" or whatever, and that "geek" losing its disparaging connotation is probably a permanent and expected symptom of this fundamental change.
A computer geek has always and still is someone who is skilled with, and perhaps derives pleasure from working with computers. But 10 or 20 years ago people like that were far from the mainstream. Since it is, of course, the mainstream that decides what is and what isn't cool, and anything that differs from the mainstream is pretty much by default uncool, computer geeks were uncool.
But now computers and so ubiquitous that if you don't have basic computer skills you are actually outside of the mainstream and therefore uncool. Hell we have file extensions (e.g., .mp3) that have made it into the common vernacular. But these tables have only recently turned, so luddites don't get it too bad yet, but the gap is only going to widen with each successive generation and pretty soon if you don't have some basic IP skills and know your way around photoshop and bittorrent you're going to be a bit of a social retard.
And all the people who used to be computer geeks 10 and 20 years ago will be the equivelant of todays sports stars