They are not used at the moment and there is no plan to make them visible. You can do it yourself by overridding the CSS.
Note that these property name won't appear for content areas.
Would be nice to have that option in a future release as DOPE fields are fairly anonymous.
There seem to be some black default labels for the DOPE-fields hidden with css. (display:none)
Anyone knows how to "activate" them?
Screenshot with the labels visible: http://imageshack.us/download/201/editlabels.png