If the mobile market is a war, the battlefield is shifting.

As VentureBeat’s Devindra Hardawar recently wrote, it’s no longer a contest between the Apple iOS and Google Android mobile operating systems. Microsoft is about to shake things up in the tablet arena with the introduction of the Windows 8 operating system, which you can download in beta form now. Whether or not Microsoft succeeds, the market is about to change forever.

This new, third factor is a wedge that will dramatically shift the landscape for tablets and smartphones, but in different ways for each.

You can see the stakes of the battle in the graph of computing platform shipments by Horace Dediu of Asymco, shown above. It’s an amazing chart, showing the life and death of computing platforms over the past three and a half decades.

Full story: Dylan’s Desk: Microsoft is about to drive a wedge into the mobile market | VentureBeat.