I always get the combo. So I can watch the Blu Ray and loan the DVD to my friends and family who don't have a Blu Ray player or so I can take it with me and play it on my laptop when I go on trips.
i wanted the digital copy and to ensure I get a copy. besides... blue ray comes out first. I wouldn't be able to buy the DVD till after the 20th. I don't see what the problem is. There are many people out there who wish to own just the blue ray but not the DVD.