Gartner: PC shipments slip 6.9% to 82.6m units in Q4, as 2013 sees the worst yearly decline in history - The Next Web

On a related note, see Closing Windows: Microsoft and its platforms are nowhere to be found at CES (The Verge)

"The PC market continues to be in free fall, having now seen its seventh consecutive quarter of declining worldwide shipments. Worldwide PC shipments dropped to 82.6 million units in the fourth quarter of 2013, according to Gartner, a 6.9 percent decrease from the same period last year.
It’s worth emphasizing that this past quarter resulted in a total of 315.9 million units shipped in 2013, a 10 percent decline from 2012, and the worst decline in PC market history. The overall shipment level was equal to the one in 2009."

Gartner: PC shipments slip 6.9% to 82.6m units in Q4, as 2013 sees the worst yearly decline in history - The Next Web