The fedora 10 .repo file gives a 404 error. By getting the Fedora 9 repo file, and changing all 9's to 10's, I was able to create the correct file.
However, since I already had a 9.8.3 s3cmd from Fedora, which failed due to file name problems, I'd suggest getting Fedora to take a somewhat newer version is a good idea in any case. Will there be a Fedora 11 version of your repos? Will Fedora 11 have the latest and greatest? Inquiring minds want to know.