Not yet, but I think I have found a workaround.
My MainForm is set as Utility and placed outside the visible area. I then use a transparent Form to hold the actual "Form" Pane. The issue about this solution is that when we hover the taskbar (not the system tray), the preview is based on the MainForm and thus is blank.
I think you are refering to a Windowsfeature. The Previewwindow comes from Windows
i dont know wheter there is an Windows api for that (Changing the previewwindow)