After putting in the Sametime Contact List portlet, I tried to view the People Palette but it is not showing. On IBM support page - Theme does not allow the addition of portlets to flyouts. This is a solution for Portal 6.0. The people finder portlet in the page is automatically maximise thus any additional portlet is hidden. If you restore the people finder portlet, you can see the portlet that is added.
In WPS 6.1, you cannot use the fix from the list. The fix can be done at the theme page, flyout.jspf. On the line
You can remove the portletWindowState='Maximized'. This will show the portlets in default state. Thus when open the people palette page it can show multiple portlets immediately.
This also applies to the Content Palette page.