The press release says,

This partnership pairs a respected and independent source of green building information with a platform that enhances the usefulness of green product information. The GreenSpec Directory helps the green building community find sustainable products, while ecoScorecard offers an effective way to identify and evaluate products against every significant environmental rating system.

ecoScorecard is a web-based system where manufacturers provide detailed, SKU-level information about its products. Those details are run through a calculation engine to produce submission documentation for LEED, GGHC, Labs 21, CHPS, NAHB, Re:Green and third-party certifications. Verrry handy for architects, designers, and other building professionals. The two systems aren't interchangeable — not all products in ecoScorecard will be listed in GreenSpec, and vice-versa. The collaboration provides users with a combination of ecoScorecard's thorough reporting with GreenSpec's independent review process. This partnership is similar to the arrangement between GreenSpec and the Construction Specifications Institute's GreenFormat program. BuildingGreen doesn't charge for listings, or accept advertising. The editors have sole control of product selection and product descriptions. For information on how products get listed in GreenSpec, see the article How do products get listed in GreenSpec?