fedora-release for f15 from f14 - is this a bug?

[mike cloaked]

I was starting to run through a yum upgrade from f14 to f15. So, as I
have done previously for other upgrades for versions up to f14, I
downloaded the f15 fedora-release-f15 rpm, and tried to install it
before yum upgrading.

The terminal session went like this once I was root and in the
directory containing the rpm:

[root at physics30 ~]# cd /home/mike/Documents/f15/
[root at physics30 f15]# ls
fedora-release-15-1.noarch.rpm
[root at physics30 f15]# rpm -q fedora-release
fedora-release-14-1.noarch
[root at physics30 f15]# yum localinstall --nogpgcheck
fedora-release-15-1.noarch.rpm
Loaded plugins: langpacks, presto, refresh-packagekit
Adding en_US to language list
Setting up Local Package Process
Examining fedora-release-15-1.noarch.rpm: fedora-release-15-1.noarch
Marking fedora-release-15-1.noarch.rpm as an update to
fedora-release-14-1.noarch
adobe-linux-i386                                         |  951 B     00:00
rpmfusion-free-updates                                   | 3.3 kB     00:00
rpmfusion-nonfree-updates                                | 3.3 kB     00:00
updates                                                  | 4.7 kB     00:00
updates/primary_db                                       | 4.7 MB     00:06
Resolving Dependencies
--> Running transaction check
---> Package fedora-release.noarch 0:15-1 set to be updated
--> Processing Dependency: fedora-release-rawhide = 15-1 for package:
fedora-release-15-1.noarch
--> Finished Dependency Resolution
Error: Package: fedora-release-15-1.noarch (/fedora-release-15-1.noarch)
           Requires: fedora-release-rawhide = 15-1
           Available: fedora-release-rawhide-14-1.noarch (fedora)
               fedora-release-rawhide = 14-1
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

Is this a bug or am I unable to use this technique any more? (it
worked fine when I was upgrading from f11-f12, f12-f13 and f13->f14)

Thanks for any suggestions.

-- 
mike c