Hello:
Maybe time is already telling. The research group IDC released a report today that says PC sales were down 13.9% compared to the same period year. It contains the phrase "PC Shipments Post the Steepest Decline Ever in a Single Quarter". While some of that is attributed to the popularity of tablets, the report also contains the line "At this point, unfortunately, it seems clear that the Windows 8 launch not only failed to provide a positive boost to the PC market, but appears to have slowed the market". See IDC report on PC shipments Q1 2013

This study includes all sales, both consumer and commercial. The report doesn't provide statistics on the adoption rate of Windows 8 in corporate environments but I would be comfortable in saying that's very low (except in organizations without an IT department and who buy from a consumer-oriented retailer).