I got further observations via email:

"[..] the cost of doing a full-color coffee-table book would be prohibitively expensive, and [..] perhaps the only way of offsetting this would be to line up a list of "name" authors who might write essays, such as Mary Cantwell did in the New York Times several years back about "Holden Caulfield's New York." This might make publishers less jittery about the expense, but would still make it unlikely that any would take the chance, based purely on the risk/reward factor, not on anything to do with the merit of the project itself. (Such is the way the book industry functions.)"
- a literary agent and former editor

"Whatever you decide to do, the time is now. There will never (probably) be more public interest and excitement [regarding] Salinger/his works than during the year of the 50th anniversary of Catcher."
- a book's editor