A suggestion:

For implementation details, have a look at kciconsbox -- it's even in python!

The need to minimize and handle multiple sessions suggests (to me) a possible interface for multiple sessions. Have one window with a listbox: one line per defined session, and one labeled "New session". One of the following schemes will be used:

1. Each normal line has
   • checkbox, which is checked when a connection (and hence an rdesktop client window) exists
   • label, which uniconifies the client window when clicked
   When switching to the control window, all client windows are minimized.
2. Each normal line has
   • Connect/Disconnect toggling button
   • Checkbox for window/icon status
   • Label; when clicked, switches to that window.
   When switching to the control window, all client windows are left alone.

Or some other variations...

The "New session" line is different, and provides a quick way to start a new session; clicking on the label pops up a screen much like the current one, with options of connect, save, and cancel. Connect will connect (showing up in the control window's list as "Unnamed session 1", with 1 incrementing, (or perhaps with the hostname?) and disappears as soon as it's disconnected. Save saves into the list, and cancel cancels...

Hmmm... I'm not seeing where editing/removing existing connections fits though; this concept needs some work there.