Windows 8's fortunes in 4 charts.

Chart 1: Windows 8's marketshare growth lags behind Windows 7's, tracking from the first month of retail sales for each version of OS.  This chart alone tells you how badly Windows 8 is trailing.  (Note that the first month of retail sales, both OSes already had small market shares (not starting from zero), due to pre-release installs, and even then, Windows 8 preinstalls trailed Windows 7.)

Chart 2: If Windows 8 was merely suffering from a shift to tablets, it didn't show up during Windows 7's marketshare growth.  Note that right up until Windows 8, despite drop in shipments, Windows 7's growth in marketshare continued to increase.  Windows 8 is under attack from more than just tablets.

Chart 3: Mac OSX (implied but not shown) has been eating at total Windows OS marketshare for some time.  Because IDC's numbers are not seasonally adjusted, there is a sharp falloff between each Q4 and the following Q1.  However, over time it's clear that total PC shipments have declined of late, and most of the burden is carried by Windows computer suppliers, indicated by the drop in total Windows OS marketshare.

Chart 4: The concurrent flatline of both Windows 7 and all Windows OSes marketshare in the last six months, in conjunction with the shrinkage of total PC shipments, points to a real shift to tablets.  Note: Windows RT's marketshare does not show up in mobile OS tracking, possibly an indication that it has not yet gained 0.01% global marketshare.  The shift to tablets is a shift away from Microsoft's desktop and tablet operating systems.

Bottom line: Windows 8 and Microsoft's OS ambitions are under attack from many angles.

So, the question is: When XP support ends in April 2014, where will businesses and governments shift to?

It'll likely be split between Windows 7 and 8, and ChromeOS.  A move to Mac OSX will be too difficult a transition for most.  The move to Windows 8's UI, combined with the incrementally higher cost of moving to touchscreen capable devices, would seem to limit Windows 8.  In fact, if new computers are shipped with Windows 8, they might be downgraded to Windows 7.  Since ChromeOS is not much more than a browser as an operating system, it would be extremely easy for people to shift to ChromeOS.

The future is not so bright for Windows 8, even after an 8.1 update.

Data sources: Netmarketshare, IDC