OK, Mark's comments got me to thinking that maybe I had gotten a little too excited.  I called Duncan Hines again today and pressed for more detailed info.  It turns out that the cake mixes that I found are indeed the new recipe with no milk.  However, the mixes are still processed on shared lines.  They do not recommend that anyone with food allergies use these mixes.  I expressed my concern to her that the labeling on these mixes is misleading.  She said that eventually these mixes will be processed on separate lines, but couldn't tell me when that would happen.  I asked her how I, as a consumer, could tell that the processes had been changed.  She said that there would probably be some sort of packaging change.  But I really doubt that since they have already changed their packaging.  I don't understand how they can get away with the OU marking either.
 
I called FAAN to make them aware of the situation and the woman there told me that FAAN has had a lot of trouble getting good information from Duncan Hines.  FAAN was not even aware that there was going to be a change to dairy-free.  She advised waiting a long time before trusting their mixes to be safe for the dairy allergic.  It's so frustrating when manufacturers are so difficult.  I'm sorry if this has caused any confusion for anyone!
 
Sandy