The cynic in me feels like money had to have changed hands in order for this to have happened (maybe Google is an investor in GuruNet, maybe GuruNet paid for that placement), but the optimist in me says that Google is still a weird little company where the members of project teams can stumble across a better resource that will make their users happier and more productive and implement it on the live site quickly, even if the company that provides that resource could be considered a competitor.
Marissa Meyer, Product Manager for Google, was kind enough to respond to my query about it:
This decision was driven off of concern for our user experience. We are not paying answers.com for this service nor are they paying us. They were willing to work with us and design a website that we felt represented an improvement for our users over what was offered on dictionary.com (no pop-ups, dense information presentation).
That a $50 billion American company is so focused on the experience presented to its users, well, it’s pretty impressive.