Netflix for Online Catalogs?

We read Publisher's Weekly at work, which reviews books several months before their release. In addition to looking for books to add to my library's collection, I also keep a very lengthy list of books to read. If it's a book by a popular author, or something that has gotten a lot of press, I check to see if the public library has it in their catalog as "On Order". If they do, I put it on hold.

Inevitably, 6 books come in at once. And I don't have time to read them all. So I have to return them and reorder them. Ad nauseum.

I really wish there was a more sophisticated mechanism for limiting the number of books waiting for me at one time. Like a Netflix for books. But free through the public library and more advanced, because it would need an override option for books you want to get as soon as they come in. Like the latest book by your favorite author. Or the slew of Halloween music CDs and Halloween decoration books I just ordered from the public library (I'm sure they love me right now).

Anyone know of anything like this in the works? How about you, Innovative Interfaces? Or you, all you open source catalogs out there? I'd love to see this option, but have no idea how difficult it is to implement from a technical perspective.