Comment 4 for bug 742544

@Sebastian, I found that you can change the screen the launcher shows up on by editing ~/.config/monitors.xml. If one of your displays is designated as the primary output in that file the launcher will show up on that display. Find the "output" item for your desired primary display in that file, and then find the sub-item named "primary". Change the value to "yes" for that output, then log out and log back in. That way you won't have to hurt your neck while you wait for a final solution :-)