"Hadoop is where science meets big data – it's the technical underpinning that powers our innovative consumer and advertiser products on the world's most-advanced digital canvas," says Blake Irving, Yahoo Executive Vice President and Chief Product Officer. "Yahoo!’s cloud and Hadoop make it possible for Yahoo! to rapidly personalize our content and advertising, and deliver highly relevant experiences, while maintaining the trust of our 600 million users."

Yahoo says Hadoop plays a key role in its home page, Yahoo Search, Yahoo Mail, and other properties.
"Businesses across all sectors are looking for ways to leverage the vast quantities of data they are accumulating, and Apache Hadoop is an efficient solution for processing data at scale," says Melanie Posey, research director at IDC Research. "Now organizations of various sizes can leverage Yahoo!'s Hadoop investment and deployments to run it on their own systems and build out their own Hadoop deployments without starting from scratch on internal science experiments."
Specifically, Yahoo announced the beta release of Hadoop with Security and Oozie, the company's workflow engine for Hadoop. This means enterprises will benefit from better controls for managing business-sensitive data, according to the company.
There has been a lot of talk about the deal being bad for Yahoo and good for Microsoft. This may or may not be true, as it's really way too early to tell for sure, but Microsoft CEO Steve Ballmer has been doing his best to try to convince people (mainly Yahoo shareholders) that Yahoo is in fact getting a good deal.