PC sales keep declining?

What is going on in the PC industry? Is it true that PC sales are declining? I get the feeling that Tablet and other small hardware will keep growing until the point where PCs are no longer viable?
In October 2012, Microsoft debuted Windows 8, which received mixed reviews, and sales have been muted compared with past Windows launches, according to bnn-news.com.
What is going on?
source: http://bnn-news.com/pc-sales-declining-92852