This was from a few weeks ago, but it makes for an interesting insight into what some of the big players of the publishing world are doing:
When the book wars sweep across the galaxy, and the blood of publishers runs down the gutters of every interstellar metropolis, the resource we fight for will not be paper, or ink, or even money. It will be time. For our readers, time is the precious commodity they invest in every book they decide to purchase and read. But time is being ground down into smaller and smaller units, long nights of reflection replaced with fragmentary bursts of free time. It's just harder to make time for that thousand-page novel than it used to be, and there are more and more thousand-page novels to suffer from that temporal fragmentation.
Read the article here: http://io9.com/tor-com-explains-why-novellas-are-the-future-of-publish-1685440234