For years, IDC has ignored ARM as a player in personal computing. That has changed.
“For the first time, IDC is forecasting PC microprocessor units by processor architecture, including those based on x86 and those based on ARM. By 2015, IDC expects that over 13% of PC processors will be based on the ARM architecture.“
That sounds like they are still ignoring smart phones and other gadgets as PCs and 13% is the near-term invasion of x86-space. I am sure many believe that will never happen for dozens of reasons but it is reality. Accept it. If you count smart phones and tablets as PCs, 13% should happen real soon, like 2011. That’s why M$ is getting on-board.