Microsoft is pulling out all the stops with Windows Phone 7 in an effort to get the right message across to both consumers and developers and get them on board. It is reported that Microsft will spend close to a billion dollars to do just that. So far from what has been shown I'd like to think that it's worth it but only time will tell the story.
Thus far Microsft has surprisingly held onto 16% of the smartphone market due to it's years of Enterprise use. Most business in one way or another are already invested in a Microsoft infrastructure. Microsoft integration is always a plus in the enterprise world (one area where Microsoft excels).