Every print publication that thinks about its future has wondered whether it should go web-only, and seldom is the argument for doing so stronger than in the case of law reviews, which lack glossy pictures, pass-around interest, or bathroom-stand appeal. No law school wants to give up and go web-only because it seems unprestigious, but the undeniably tony HLR could solve that problem by going first. Aside from saving on printers, there might be practical advantages such as not having to hold back an announced issue because one article runs late. ...One way or another, some scholarly apparatus will be found to publish meritorious longer articles that advance the mission of serious research into the law. But when it comes to discussion of timely controversies, slash-and-thrust debates, and other forms of writing that people actually go out of their way to read, there's no doubt where talented legal academics are headed: to blogs and other shorter-form online publications.
I think Walter Olson's basically right. but there are so many obstacles. First mover issues. Revising the tenure process to accept non-traditional scholarship. Inertia. And so on.