The proposals need to include details on both the content as well as info on "technical integration, training and support, collection development tools". This pilot will launch in June 2013 and if successful it will be expanded to include all MLS members that choose to participate.
Their membership rolls list 1,700 libraries in a state with a population of 6.6 million. That means that if a significant number of MLS members sign up after the pilot is expanded then this would be one of the larger digital library programs in the US, if not the world. I doubt that the MLS program will support a larger population than the NYPL, which currently supports 3.5 million NYC residents, or the Los Angeles Public Library, which serves a population of four million, just to name a couple examples, but this digital library could still end up with a broad population to support.
image by Muffet