That catalyst between engineering and sales is an activity called "product marketing" and the output of that activity is "productization". To specialize in product marketing can be considered an occupation in itself. Little heralded beside its better known full marketing departments of traditional B2C, or the flavour-of-the-day social marketing mavens, product marketing is about the structured and disciplined definition of exactly what an organization will sell.
A sales guy explains why product marketing is the bridge between product and sales. Nice post for people in product management and marketing to share internally.