From what I can gather, p7zip-plugins (aka 7z) is a plugin-based version of 7za (p7zip), and doesn't really need or require it at runtime.
Good catch. This makes me wonder if the plugins sub-package should still be called like that. Anyway, I'll remove the requirement as my own testing does indeed confirm that the main and the plugins packages are now independent.
p7zip-9.20.1-1.fc15 has been submitted as an update for Fedora 15. https://admin.fedoraproject.org/updates/p7zip-9.20.1-1.fc15
Package p7zip-9.20.1-2.fc15: * should fix your issue, * was pushed to the Fedora 15 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing p7zip-9.20.1-2.fc15' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/p7zip-9.20.1-2.fc15 then log in and leave karma (feedback).
p7zip-9.20.1-2.fc15 has been pushed to the Fedora 15 stable repository. If problems still persist, please make note of it in this bug report.