Comment 131 for bug 375145

@marco-parillo there's really no need for that option since it's not something the user wants to change except if he changes desktops.

What I would do is a separate ubuntuone-kde-integration package that handles autostarting the control panel that way. It would be a tiny thing, basically just a desktop file. OTOH, the name feels wrong since like you said xfce needs it too (and I assume so does LXDE and minimal WMs).