Objet recently introduced its largest 3D printer to date. The Objet1000 has a build volume 1 meter wide. What the machine illustrates to me is that some of the most inhibiting limitations of additive manufacturing today—one of which is build size—are being overcome.
This machine is for prototypes, including functional prototypes. A similar machine making end-use metal parts might be still a ways off … or not. In fact, platforms do exist already for additively producing large metal components. See examples here and here.
To get a sense of how an operator interacts with the Objet1000 to make a large part, watch this video.