This is both interesting and a little confusing - largely because details are sparse, I suppose. Microsoft looks like it's planning to move to an "Apple-like" model, where it offers yearly OS upgrades, and what may be the first part of this approach is codenamed "Blue".
TheVergeOriginally unveiled by ZDNet, the update on the Windows side, due in mid-2013, will include UI changes and alterations to the entire platform and pricing. We’re told that Microsoft is aiming to make Windows Blue the next OS that everyone installs. The approach is simple, Microsoft will price its next Windows release at a low cost or even free to ensure users upgrade.