There have been a lot of shifts with the Microsoft-owned Skype team recently with the long-term goal of bringing development of the VOIP service closer to Windows 10. One of those changes is being announced by Microsoft today, and it has to do with the sign-in process.
Currently, you can sign into Skype using your original Skype name or your Microsoft Account. Going forward you will be able to do the reverse: sign into other Microsoft services (OneDrive, Xbox Live, etc.) with your Skype name. From the Skype Blog:
You may have recently noticed a few changes in the look and feel of your Skype account. We've been working to bring Skype and Microsoft closer together and are excited to announce that soon you will be able to use your Skype Name to sign into other Microsoft services like Xbox, Office and OneDrive. With a single sign-in (and an email address for certain services) you will soon be able to have fun on Xbox Live, access your photos and docs through OneDrive, check your email on Outlook.com, and connect with your friends and family on Skype.
If you have noticed some changes to the Skype sign-in screen, password change and account recovery flow, that's because these are now managed by Microsoft. None of these changes will affect your ability to use Skype - as usual; you can still sign in using your Skype Name.
This shift is a nice streamlining effort that will likely benefit Skype users who are currently not deep into other Microsoft services. One of the biggest obstacles in getting people to switch to services is the barrier to entry including signups and logins. By letting Skype users sign into Microsoft services with no barrier, it should make it much easier to do more in Windows 10.
Skype always was the outlier in the Microsoft Services world regarding accounts. With this single sign-in to access all Microsoft services, Skype user accounts are now only different on the surface.