I am pretty sure DNA has nothing to do with the renaming of the stapeliads in this instance - I wonder if they had done a DNA study it would have stopped it from happening. As far as I know one of 'THE' experts on these plants has published a reassessment of the genus in a scientific journal (so a little harder to come by - I am working on it) where essentially the base conclusion is that for the Stapeliads, Huernias, etc. if you follow the strict rules of botanical nomenclature that the first name used to describe a specimen of the species gets priority in terms of name given to that plant or genus by any follow up description, which apparently means that going back to Linnaeus 1753, Stapelias, Hoodias, Huernias, etc all fall under Ceropegia for the moment...
This may change again as other experts will respond to this, but in essence convincing arguments will need to be made to reverse this - this is pretty similar to someone publishing a while back that a whole bunch of south American cactus species should all fall under the name Echinopsis... though here it was done for another reason than name priority but it led to a similar mass confusion of plants having to be given new species names because now that they were all Echinopsis there were multiple duplicates. There is currently a movement going on to reverse this decision because it turned out that if you were going to be really strict in applying the rule of why something should be called Echinopsis iso its original name more or less all south American cacti would have to end up being named Echinopsis... but that has not yet found itself into some of the major plant lists that are published... At least not when I last checked.
