The shadow was added in a late 1.6 rc and testing showed it needed some more work (particularly with dragging, resizing, show and hide effects, certain browsers). So it's out for now. We'll bring it back when it's ready.
As part of our transition to the new jQuery UI CSS Framework ( <a href="http://jqueryui.com/docs/Theming/API">
http://jqueryui.com/docs/Theming/API</a> ) in 1.7, the modal overlay is now styled in css instead of as a js option that you pass to the dialog plugin (which would add an inline style). This is most easily done by ThemeRoller, but can be done manually as well:
.ui-widget-overlay { background: #aaaaaa; opacity: .3; filter:Alpha(Opacity=30); }
- Richard