My quick "what would you do if you where netflix" tells me is that this is an economies of scale game.
1) If they do pay per view, they are doomed, as their client base likes the fixed price above anything else.
2) If they want to become and HBO, they are doomed, as they are not a premium channel, but rather the opposite. If the offered a greater reduced number of unique shows, I'd pass and look for something more netflix like than what they'd become
3) As premium content disappears from Netflix, delays get introduced, etc. it opens windows for a different dominant player.
4) If the "buffet" streaming industry fragments, exclusive deals will mean reduced income, as many people are more akin to give me good options but not necessarily all, keep the price down. So studios will strike some exclusive deals that are time limited. But that would erode, as now Amazon and others will offer better deals for share. But then, they'll have a smaller base and therefore less money and a larger collection to sustain.
5) Netflix can't accept a fragmentation, but doesn't have a solution yet. They can only solve it through product management (adjusting what they sell).
From there it flows naturally (for me at least and I have though of many objections that have answers) that the only way to do it is to offer more money to the studios, and some neutrality in the model.
This means - following their core that took them to the top - combining fixed price to the consumer but pay per view to the studios. Their only chance is meeting both ends in a happy way.
An the only way to do that is to limit the number of shows you can view a months. After all, netfli is any dvd you want for a fixed price. If you want more than what the natural limit of going through mail offers, you need 3, 4 or 5 at a time.
How that would work is offering you the standard channels all that your eyes can eat (all the non premium stuff) and an option for the premium stuff that would work exactly as the DVD option, with instant play of up to 5 premium movies a month, then for a little extra 8 movies a month and then 12 and maybe 15....for a fixed price.
Now, the difference is that they will have to with those studios that are sharing their movies and buy their business model. If your movies is not so good, do the fixed price for the unlimited more broad service. If your movie is premium (people will chose your movie even if they can only chose 5 of those a month), then go for the premium agreement and netflix will share the revenue based on views.
It's just adding more sense to the pay per view.
Now, I am not saying this is the best. But it is what I would do if I where the netflix management caring for my long term success. The studios would have a platform can be neutral.
For the consumer, it means knowing exactly how much you'll spend - a fixed rate. The sense of unlimited movies is preserved, a little more money is extracted, as time passes the streaming costs go down, the network grows, etc.
The only risk is having the studios do this without netflix help. BUT, that doesn't work, you'd need an independent firm. They are better of sharing stocks of netflix and sitting at their board, and take them as the standard.
They would then only add the "buy" option for the movies, and share the largest chunk of that with the studios.
They key to everything here is making the case with the studios that a fragmented landscape is going to slow down sales for several years, bother the consumer (which will spend less in movies than they are doing today, and - overall - just reduce the industry growth).