HBO subscribers can now view HBO content via broadband, including the archives (Yes, that includes the Sopranos). But only subscribers can sign up.
This is a smart and natural extension of the HBO brand, and should be the model for other premium services.
I'm not surprised that Showtime is not renewing its licensing deal with Netflix for legacy content- they feel it cannibalizes their other revenue streams.
But at some point your legacy content will have outlived its shelf life, and Netflix will be the last available revenue stream. Everyone who wants to own "The Larry Sanders Show" or "Band of Brothers" on DVD probably already has it.
The good news for content creators is that there is revenue all through the long tail. The hard part is finding the right delivery platform for each package, and pricing it fairly for all involved.