BD disc only for me. The digital download thingy is a waste of time and a pain in the ass (I ran into some trouble trying to download a few of them into my iPod).
I don't mind getting a DVD with the blu-ray. I have DVD in my bedroom and blu in my living room, so it can be beneficial. At some point I will get blu for the bedroom too, so it's not a huge issue either way for me. I still have so many DVDs that I can stay content for quite some time.
The BD disc only with possibility for a rebate for my old DVD. I have never seen a BD come with that.