Ok, it's not PROOF, but here are some serious hints. Open the sys pref screen shot and open your current 10.3 sys pref window and put them side by side. See how you have the widget in the upper right to open and close the dock-like area for control panel short cuts. There is a "show all" icon (with text) on the left and then space on the right for frequently used control panels.
Proof #1) It has a show all text icon. There is no space for panel shortcut icons. Where is the dock functionality? You think apple REMOVED functionality?
Proof #2) There is a back and foward button. Why? All control panels have only screen. If there is no dock-like functionality so you cant switch from 1 panel to another without showing all anyway (besides using the menu bar). The buttons have no logical funtion whatsoever. That I can think of anyway.
Proof #3) The search box would not funtion if you were on any screen but the show all screen as it gives results by high lighting different panel icons. If you were in a control panel, would typing in the box bounce you out of the screen you were in? I don't think so. Would it just not work in any but the show all panel. I don't think so.
Proof #4) In the 10.4 screen shot there is only a text icon. In OS X revisions have you ever known apple to REMOVE icons? it seems they only add more and more.
Proof #5) As someone else mentioned, there is no true title bar. Some apple apps do not have a true title bar, but usually only when it has other items that make a clear distinction between title bar and body. Look at safari, no true title because of the address box directly beneath. Look at the mail app main window, true title bar because there are only a few icons beneath making no obvious deliniation.
Summary: To me it looks like they basically just took a safari window and pasted in a picture of the system prefs.
Whadda ya think?