It's no surprise that Microsoft's Bing app includes voice search, maps, directions, search suggestions, and location awareness. Besides these being features common to Bing.com and to the Bing application on other mobile platforms, they're also necessary to compete with Google Mobile App for iPhone.
More surprising is Bing's stylish layout, which opens on the image of the day in the background (this doesn't appear to be customizable); a rounded, six-panel grid of buttons to jump you to movie listings, maps, directions, and more; and a drop-down menu on the search bar lets you filter your searches in all those categories, save directions. Bing dispenses walking and driving directions, but doesn't yet include directions using public transit, as the Google Mobile App does. You can, however, advance through the turn-by-turn directions one at a time by swiping your finger.
Bing for iPhone lacks some of the extras of other mobile Bing apps, like the capability to lay down pushpins on the map and save locations, and the capability to view multiple locations on the map. The absent features in the iPhone app indicate the direction of Microsoft's plans for Bing's growth on iPhone. Overall, though, Bing for iPhone is a viable alternative to Google's 1-2 combination of the Mobile App and the iPhone's default, Google-driven Maps app.