Microsoft's cloud storage service, OneDrive, is quickly becoming more than just a basic locker in the cloud. With Windows 10, Microsoft is now making it possible to store app data on OneDrive, along with other aspects of your install.
Inside the 'Update and Recovery' settings tab inside Windows 10 build 9901, the 'Backup' option gives you toggles for sending data to OneDrive for, well, backup purposes. Along with app data, you can store your Start layout, passwords, favorites and 'other' system settings to OneDrive.
If you are thinking some of this sounds familiar, you are right, as with Windows 8, using your Microsoft Account, some of this data was synced already. What appears to be changing is the ability to store it in OneDrive and having more control over what data is syncing across the platforms.
This addition is new in 9901, in 9879, there was no 'Backup' option available in the 'Update and Recovery'.
Prior to this leak, rumors circulated that OneDrive may be integrated into Windows 10 as a full backup solution for the OS. With Office 365 users getting unlimited storage and even those cheap Windows tablets getting 1 TB, the idea seemed plausible. With the discovery of these new options inside Windows 10, it does seem that Microsoft very well could be heading down that path.