I feel that peer-reviewed journals aren't even going to be relevant much longer. Putting aside the commercial side of it, the actual scientific quality of peer review seems to have drastically declined. Most of the referee reports I receive nowadays are trivial and superficial, even at the top journals of my subfield. I suppose a lot of research has become so specialized that an outsider isn't able to give much intelligent commentary on it either way.

As a reader, I almost exclusively look at arXiv and other preprint servers, and I find myself caring little if/when the papers there are "officially published". In fact some of the best "papers" and important references in my field are certain lecture notes, monographs, and theses that have never been "published" anywhere but arXiv.