The kipi-plugins we currently ship has a dependency on QtGStreamer 0.10. When moving Rawhide to QtGStreamer 1.0, that dependency will have to go away. Unfortunately, I haven't yet found a patch or branch porting the affected videoslideshow plugin to QtGStreamer 1.0. If it does not get ported soon, we will have to disable QtGStreamer support, and thus the videoslideshow plugin, in Rawhide's kipi-plugins.
A patch is now available at: https://git.reviewboard.kde.org/r/119073/
Built for Rawhide and F21 Branched.