I backed up my files from the preview and upgraded to the full version of Windows 8 yesterday. I haven't been able to restore using the File History application, and I have thousands of files, so it would take too much time to remove the date tags from the filenames on my backup drive (as it's messing up all paths). Hopefully there's a fix!
Apparently the old backup utility exists under the name Windows 7 File Recovery. I really do like Windows, but I don't think "Windows Backup" and "File History" would have been problematic without the rename.