Microsoft's Yusuf Mehdi and Qi Lu with Facebook's Mark Zuckerberg on a webcast from Silicon Valley today.

Facebook and Bing just updated their relationship status, and the news doesn't look good for Google. Down at Microsoft's Silicon Valley HQ today, the company's Bing search engine announced an expanded partnership with Facebook to leverage information from users' Facebook networks to improve search results.

Starting later today, Bing search results will add a new "Facebook module" with links to additional information about a particular search term, based on sites or web pages "liked" by that particular user's friends -- such as restaurant or automotive reviews. In addition, Microsoft will improve Bing's ability to search for relevant people by taking into account the user's network of Facebook friends.

But the interesting part was the comments from Facebook's Mark Zuckerberg about why the social network decided to work with its minority investor Microsoft (and, by implication, not with search giant Google) on these new search features.

"The thing that makes Microsoft a great partner for us is that they really are the underdog here, and because of that, they're in a structural position where they're incentivized to just go all-out and innovate," said Zuckerberg, via webcast. "And when you're an incumbent in an area, no matter how smart you are, there's just always this tension between trying to innovate and push new things, and trying to preserve what you have. And we've never felt that with Microsoft."

There's more on the Facebook integration with Bing in this Microsoft blog post. Also see this video. The companies say the integration will be expanded as they work together over time. Microsoft holds a minority stake in Facebook, following a $240 million investment in the social networking company three years ago.

Update, 1 p.m.: Zuckerberg expanded on his comments about Microsoft during a Q&A with reporters at the event. Here's what he said.

We're trying to build a platform. Fundamentally, this is not about working with just a single company. Over the long term, we would love to work with everyone. But the question that I think you have to ask is, why is Microsoft the company that's' being innovative, and doing this before everyone else. And I think that's fundamentally tied to the culture that they have now and their market position and what they're trying to accomplish. They see this as a huge opportunity. And if you look at a lot of companies that have done social integrations, they tend to not be the incumbents. They tend to be the disruptive force that's trying to do something different. And I think that there's just something really valuable to working with those folks. Those are the people we seek out, and that's one of the reasons why we think that this is going to be such a good partnership for a while.

Google is seen in the industry as a rising competitor to Facebook, with plans to expand its own social networking offerings, possibly under the name "Google Me." Microsoft has been working with Facebook to incorporate elements of the social network into its Windows Live online services.

Microsoft and Facebook declined to disclose the financial terms of their expanded relationship when asked to provide details during the webcast.