Comment 6 for bug 775717

There is already an open discussion here:
https://bugs.launchpad.net/gnome-panel/+bug/767095

Anyway I found a solution for the time being. (ubuntu natty 11.04/64 bit/gnome2)

The configuration of my top panel is [from left to right]:

[Main Menu] [ Notification Area] [Indicator Applet Complete]

The key point is the Notification Area. If it is not locked you can move it. If you give it enough space to display the skype icon, it will appear. The problem is that it doesn't move/resize automatically. Try it. It worked for me.

N.B. It's not dynamic, you have to quit skype and open it again.