Looks like Google is taking search to Microsoft's door step with the new Google Search App for Windows Phone 7, seeking to compete with BING.
But the Google Search App, is different from the way it performs on iOS or Android platforms. Just like BING app, it does not search the device for contacts or other information. But it does well for web search. Google Search App offers search suggestions as you type and you can then choose from the suggestions just like on iPhone or one of the Droids. Another feature the search app brings is geolocation support, providing local search results.
The Google Search App for Windows Phone 7 is in the Zune Marketplace, right now.
Google Search app for Windows Phone 7 - in the Marketplace now - Official Google Mobile Blog