I was wondering if an online store would want to do something with another series the way Another Universe has done it with MSCL (pending cooperation by the copyright holders, of course).
I think that some would jump at doing this. It is all up to the content owners, really.
What happens is that there will be a title with little interest at retail, and the studios will have no plans for it. Eventually, someone will ask them if they can buy the rights and the studios suddenly will act like it's the golden goose.
I predict that the studios will try to do a lot of it on their own, and they won't put time or attention into the extras, or the collectibility factor. They think that the internet means that all entertainment must now be reduced to downloadable commodity. Eventually, they will say that there is no money to be made.
The truth is that the die-hard fans are much more quality sensitive than price sensitive. They would rather see a studio put out a $125 set than a cheapo $50 set with no extras, and no care. If they do it right, though, the money is there.