They apparently (the twitter message isn't actually the company statement) plan to return it "sometime in the future" and "if it might be free or if it will cost" is TBA:
http://www.windowscentral.com/windows-10-will-include-option...
The Media Player capabilities, if you have them in your Windows edition, will be for ever deleted. Just so.
Moreover, note that the upgrade can reduce the functionality of your notebook: Microsoft made the deal with the hardware producers about integrating hidden partitions to allow the recovery from the hard disk, but the upgrade process will just make sure that the Windows runs, not that your recovery from the hard disk functionality, managed by each hardware vendor independently (based on the recommendations from Microsoft) would be preserved.
I don't use the recovery mechanism, but I do use backup. When the recovery partitions aren't right, the built in backup (which was kept from Windows 7) doesn't work on Windows 8.1.
The same story happened with the transition from Windows 8 to Windows 8.1 (I have such a notebook).
Anybody knows if the "Windows 7" style full disk backup survived in Windows 10?