Microsoft recently announced a number of changes to its Windows 8.x and Windows Phone platforms that underscore it is doubling down on Windows.

Breaking Friday was the news that Microsoft will lower the per-device cost to OEMs to ship Windows 8.x on less expensive devices. Bloomberg’s Dina Bass wrote that for devices that sell to consumers for $250 or less, Microsoft will charge $15 for use of Windows 8.1, a 70 percent decline on previous rates.

This allows OEMs to enjoy far stronger margins on low-cost Windows devices, making the Windows world more attractive to the ever margin-strapped device manufacturer world. Also, this brings the cost of Windows on cheap tablets more in line with the cost of Windows Phone on smartphones, an important change given the coming unification between the two core Windows platforms. Microsoft is still coy on the matter, but its executives have essentially laid the plan bare publicly.

This morning at Mobile World Congress Microsoft announced a sheaf of new product changes to both Windows 8.x and Windows Phone, including improvements to the core desktop experience of Windows proper, and aggressive moves to extend the capability of OEMs to build Windows Phone handsets.

In addition to a ready-to-go template, and work to allow Android handsets to run Windows Phone more simply, Microsoft listed off a grip of new OEMs that are on board to work on Windows Phone itself; if the platform is to live and die by partners, as it has thus far (both flavors of Windows), making the lives of those partners easier is simple calculus.

The announced Windows 8.x changes — detail remains light, expect more at Build in a few months — and the Windows Phone platform improvements continue the company’s bet on both Windows, and its ability to grow a platform of its own. This means Microsoft is wagering that it doesn’t need to retrench to lean on Android, for example, an idea that some externally have floated.

What you need to keep in mind is that work Microsoft does now to improve Windows Phone is work proper to its strategy to unify that platform, and experience with Windows RT. So, the work that the company is doing to better support keyboard and mouse users is almost separate; that work is in a different use-case silo.

Lowering the cost for Windows on low-cost devices could help the company foster a new cadre of devices that will eventually run whatever the Second Windows is; so the new OEM group supporting Windows Phone implies future hardware support for what comes next. That’s important.

All the above — and I’ll have more for you in the coming days — indicates so far as your humble servant can divine from lumpy tea sediment that Microsoft hasn’t changed its course in betting that a unified Windows experience across device classes with a firm shared application development environment is a strategy worth following.

Can Windows Phone take on Android or iOS in the short-term? No, at least not in terms of developer buy-in. But a unified Windows ecosystem that helps developers build once and deploy diversely to a growing set of devices could be something different altogether, in the medium and long-term.

Microsoft is not out of the arboreal subset, but it is wagering on building something big of its own, instead of depending on others. In the platforms wars, there likely isn’t another option. It remains a question of execution.