Google announced a new Shopping APIs, that have two components: Content and Search. As part of this launch, also deprecating the Base API and replacing it with Shopping APIs.
"Content API for Shopping allows retailers to upload product data to Google for use in multiple places online like Google Product Search, Product Ads, Google Affiliate Network, Google Commerce Search, and Shopping Rich Snippets.
Search API for Shopping makes it easy for Google Commerce Search customers, Google Affiliate Network publishers, and developers to build innovative apps using product data," explains Google.
"These new Shopping APIs replace existing Google Base Data API for content providers and search apps. We're deprecating Base API and will fully retire it on June 1, 2011. For existing developers making the switch, we've provided a Migration Guide to help," write Google.
More Info: FAQ on Google Base Data API Deprecation