Someone just released an HTTP server called H2O, which is significantly faster than Nginx (especially for small files). This in itself is an accomplishment, but the reason for this development is even more important.
Current techniques used to decrease the number of asset files (e.g. CSS sprites and CSS concatenation) becomes a drag in page rendering speed in HTTP/2.
Such techniques were beneficial in HTTP/1 since the protocol had difficulty in utilising all the available bandwidth. But in HTTP/2 the issue is fixed [...]. Instead, switching back to sending small asset files for every required element in the webpage being requested, becomes an ideal approach.
Indeed, SPDY/HTTP/2 introduces a far more efficient approach to loading css/js/images/... concurrently in a preferred order, which could mean having a small number of larger files could be a less desirable approach.
Since SPDY is already up-and-available (and powering this blog), I'm sure it's only a matter of time before someone does some real-life browser testing with a small number of large files vs. a large number of small files on a website.