A play on the word "prototype", a "promotype" is a mock-up of a product that may or may not be in the early stages of conceptual design or development. A promotype's sole purpose is to generate hype with an overage of promotional glitz and glamour. The product's feature list may also be heavy on buzzwords and is designed to make life easier for the guys and gals down in Marketing.
promotypes (plural), promotypical (adjective)
See also: "vaporware".
Hiya!: If you have any examples of a "promotype" /msg me and I'll list them here.