Onedrive is simply Microsoft’s replacement name for their Skydrive service. They lost a case on the Sky name and had to change it. The change should in no way be customer affecting and all files will remain and be associated with their services. it’s just required that you log on to your account at Onedrive instead of Skydrive.
Although there are a few minor enhancements and of course the major enhancement of a fair bit of disk space for free (7 gigs) nothing significant, other than the name has really changed.