This article claims future ultrasound equipment savings of ~80%: USD$250,000 (3D) vs. USD$50,000 (2D-modified).
From the perspective of patients and medical administrators, the upside seems clear.
For (at least one?) ultrasound equipment manufacturer, this seems to imply they don't make as much profit on the likely high-margin 3D models. Curious how they and the industry responds.