No other package in a complete Gnome desktop requires yelp, so I think deja-dup should not specify it as well.
Thanks for the report. I have asked for a recommendation at http://lists.fedoraproject.org/pipermail/devel/2010-May/136335.html
deja-dup-14.2-2.fc13 has been submitted as an update for Fedora 13. http://admin.fedoraproject.org/updates/deja-dup-14.2-2.fc13
deja-dup-14.2-2.fc13 has been pushed to the Fedora 13 testing repository. If problems still persist, please make note of it in this bug report. If you want to test the update, you can install it with su -c 'yum --enablerepo=updates-testing update deja-dup'. You can provide feedback for this update here: http://admin.fedoraproject.org/updates/deja-dup-14.2-2.fc13
Fixes the issue for me, thanks! (not closing the bug because I think we need to wait until it's pushed to stable)
deja-dup-14.2-2.fc13 has been pushed to the Fedora 13 stable repository. If problems still persist, please make note of it in this bug report.