If I had to hazard a guess, which is how future history always operates, I would say that the increased popularity of SF outside of the publishing category, particularly in its "literary" strain, may be signalling the fracturing of SF. Titles that are marketed as "literary" or some other non-SF category sell well enough and get plenty of attention, while category SF is declining only insofar as its non-tie-in industry is concerned. Star Wars novels will probably sell well so long as Star Wars is on our TV screens, in our video games, and so on. You could take the Star Wars section off the SF shelf and give it a whole new space and it would still sell quite well. I get the feeling that people come to Star Wars books not for the SF tales, but for, well, Star Wars.
And, if we're being fair, SF as a genre can't survive on the backs of its "literary" takes, except where classic authors are still contributing to the field. What will save SF from obscurity is adventure and suspense, which other genres are, sadly, doing quite well without needing the SF label (though many of them are SF stories). It occurs to me that SF's possible fracture will see the "serious" forms move out into general fiction (or "literary" fiction, if you will), while SF will become a haven for the adventurous and suspenseful, encompassing the tie-in wonders like Star Wars and Warhammer 40K and bringing back a lot of what we used to call the "sense of wonder." As for "literary" SF: because it sells well enough outside of SF (or appears to sell well enough), I think we'll see it move away from category fiction in general, because "literary" writers within the SF category might see the intelligence in moving out into non-SF shelves.
But this is all conjecture. I don't know if any of this is happening; it probably isn't. All of the above is based on what I've observed in my tiny little world. Which is why I'm bringing the question to you:
Do you think "serious" or "literary" science fiction will abandon category fiction for the general fiction pile?