As much as I hate to type it... By 2019, I'd expect home computer OWNERSHIP to be on the decline.
That's not to say home computer USAGE will drop, but I expect more and more of the subscription/rental model will be taking over.
People are pretty much fed up with owning PCs. They crash, get infected, and are generally a nuisance. Besides us geeks who know how it all works, who really wants all the hassle and expense of really owning a system?
Much like the Cable/Sat TV market, I see hardware becoming secondary, almost to the point of invisibility. Most people will simply pay a monthly fee to use their web browsing, word processing, and email package on whatever hardware box is included in the subscription.
