True, that as ridiculously high ISO's are usable in the advanced DSLR world, the necessity of a fast lens for decent images in low light situations - as we used to have in the film days and older digital days - is less.
With the exception of the 50mm f/1.4 prime, the actual supply of fast lenses seems better than in the film era. And if you go back to the 1970s and earlier the zoom lenses tended to be slow by today's standards.
It is interesting though that "noisy" ISO settings, that everybody complains about on forums, are probably still better than using many films (although I have seen pretty good results from some newer color films being pushed in processing), certainly better than many of the classic cheaper films.
I think that, indoors, a f/2.8 or even f/2 lens is the minimum for shooting fast action (interestingly, f/2 might be the current "limit" for usefulness of a lens, though we'll have to see how the 5D III and the 1D X, as well as the T4i and other APS-C cameras, treat wider apertures).