What will future publishing look like? No idea. But there are some hints as to how it might develop in an article about current and future publishing trends in SF.
One thing that springs out from the article is that the short form, the novella, is likely to grow in importance. There is some sense in this as our world gets faster and faster and attention spans get shorter. It's also worth remembering that the novella died out because of cost issues as much as anything else and older works by authors such as Asimov tended to be novellas.
Magazines are shifting onto the digital format and finding more subscribers that way, especially via Kindle, something the recent history of 'Asimov' shows. They have increased their subscriber base substantially whilst lowering their costs.
The article is well worth a read, whatever genre you write in, as it contains a lot of good information and some interesting guesswork.