So an Android-based Microsoft smartphone might be a possibility and given several recent developments it seems that could be sooner rather than later.
It’s important to note that Google legally binds Android manufacturers to agreements that stipulate that Google search and the integrated Google apps suite must be a part of any phone sold and for access to the Play Store for other apps.
Given the tight integration of Google’s app suite, Microsoft couldn’t offer individual apps to replace some of Google’s offerings. Instead, Microsoft had to have a complete suite of its own to entice users to download and get them to do so through Microsoft’s own store.
You may not be aware of it, but Microsoft is surprisingly close to making this a reality.
Mobile versions of Office apps to replace Google Docs, Sheets, Slides and Forms, Outlook to replace Gmail, OneNote to handle Keep, Skype for messaging and video chat, Groove Music instead of Google Play Music, Nokia Here to replace Maps, and of course OneDrive to connect them all together and offer cloud storage. This handles your basics, and even two years ago might have been enough to help people make the switch, but Google's integration goes a lot deeper than cross-app chatter nowadays.
Microsoft needed Cortana to replace voice search and act as a virtual assistant now that Google Now was baked in to all of the search functions. Between Arrow Launcher and Next Lockscreen for personalized access to apps and features, and half a dozen clever extras like Word Lens and On{X}, Microsoft as the default on an Android phone starts to look not only feature complete, but downright enjoyable.
The one big gap in Microsoft's plan for total Google Service replacement at the moment is a browser. While there are dozens of alternatives to Google's Chrome in the Play Store, it'd be nice to eventually see Edge come to Android with some of the features that make it interesting on Windows 10.
Looking at all of these apps installed and used in place of the current Google Apps demonstrates just how close the company is to a complete thought. And given Microsoft’s partnership with Cyanogen, they may be able to pull this off without even signing up with Google!