Due to litigation and let’s face it, OneDrive fits their mantra better. One place to store all your files and documents regardless of what device you are using.
Microsoft announced back in July of the impending name change due to litigation against them by British Sky Broadcasting Group (BSkyB), who successfully claimed that SkyDrive infringed on the “Sky” trademark.
Since the announcement they have been doing a lot of work behind the scenes to make OneDrive better than ever. The official release date is still pending, but I will let you know when I hear something.
Current users will not be affected, i will just roll out to devices and PC eventually.