Microsoft's Bing app, available for iPhone, BlackBerry, Windows Mobile, the not-so-lamented Sidekick, and finally Android, is basically an alternative to Google's search suite. It's got web search, images, movie listings, local place listings, maps, and directions--just like Google. Now that it's on Android, Google's preferred platform for its best features, we can get a sense of how Bing might work with the upcoming Windows Phone 7--and how it compares to Google on Android.
The Bing app for Android isn't too different from, say, the iPhone's Bing app. You get one-touch access to Bing's search, maps, news, images, and videos, all in a pretty nice-looking package. The image search, for example, features endless scrolling--no more clicking through multiple pages of images to find what you want. I also really like the quick tab for movies, which shows all the movies playing near you, along with their play times and reviews.
There's a "local" category, which is pretty much like Google Places. Basically, it gives a list of categories--restaurants, nightlife, hotels, that kind of thing--that constantly updates to reveal results near your location. I tested out the voice search as well, and it's really pretty good--just about as accurate as Google's own, though for all I know, Bing merely taps into Google's built-in functionality. However, it doesn't follow the same commands as Google's own voice search, so saying "navigate to nearest gas station" will merely perform a Bing search for that phrase, rather than actually giving you directions to the nearest gas station.
The most striking difference is in maps. Google Maps for Android is the best mobile mapping tool in large part because it offers free, integrated turn-by-turn navigation. Bing's Android app offers listed directions, but no turn-by-turn, and I've seen no indication that Microsoft plans to include that feature in Windows Phone 7.
So how does Bing compare to Google? Pretty well, provided you're not looking for any imaginative new features--Bing on Android isn't much more than a copy of Google's existing services. I don't think many people will choose Bing over the built-in Google suite on Android, because it's not really better, and Google's integration on Android is nicely seamless. But on its own, integrated into its own OS, I could see Bing being a powerful competitor to Google.
Windows Phone 7 users might not see the need for Google Maps, in the same way that Android users don't really need Bing Maps. (Of course, both are well beyond Apple, which doesn't really have much in the way of search or cloud services.) And that's great for Microsoft. In the checklist of features Windows Phone 7 needs to pack, I think we can safely check off search, in addition to gaming and multimedia, although a little innovation wouldn't hurt.