From gnome, 'Preferences/More Preferences/GStreamer' has no icon. Also, gstreamer is upto version 0.5.1
We're past screenshot/docs freeze and this is minor anyway, so I doubt we'll fix it for this release. But maybe for next if upstream hasn't. Do we really have a menu item called "GStreamer"? I hadn't noticed it. That pretty much sucks. We should consider simply deleting the item, or at least renaming it something sane.
This is fixed now; it's called "Multimedia Systems Selector", and does have an icon.