expanding on the concept of Semantic Views/CCK, how about add "Semantic Panels" to Panels?
on the overlay where we add Class and ID, or on settings, or on a new overlay (semantic?), options could be added to deal with the elements and classes/IDs being used for the Label and Field, and whether or not to show a label.
like say, we want to use a
<span> instead of a
<div> or a
<h4>, with a class
perhaps also an option to define what the label will be, with t() support.
this could be implemented mostly for CCK/Fields, but maybe also for other things, like Page Title, Node Teaser, Node Body, Breadcrumbs, etc...