There is a very serious feature missing in KDE 4.1 which will come out next month:
You can't move items on the panel, once they are there.
There is a huge discussion ongoing, the developers say it will be possible in KDE 4.2
It is NO bug, and it will be included in KDE 4.2, but that is WAY too late.
It was possible in all KDE, GNOME, Windows, OSX versions by now - not making it possible would be a backstep.
SUSE (11.0) made it possible in their with KDE 4.0(!), so there IS already a patch.
Please vote here, vote for the
"bug" at the KDE Bugtracker if you have an account there, urge at launchpad, help to make that possible.
If you like this idea, also look at my
other ideas