Windows Phone 7 is another Microsoft product that I think is pretty awesome. I will still never choose it over Android but I wouldn't mind having one in addition to my Android of choice. To be honest with you though, it's because of a kinda stupid reason... I like it because it's pretty. I love the tiles system they use for the UI. After that, I think it might slip. Microsoft really pushes their apps with things like outlook and office. Those are apps that I dont care about... Not even a bit. I think they know that, unless you're a business, you probably don't care about those apps. Outlook isn't a big draw for most people. It concerns me that there isn't anything else in the phone that would make me want it and, even worse, there aren't many 3rd party apps compared to iOS' 500,000 and Android's 300,000 apps. I think Windows Phone 7 is around 35,000 [45,000 now, according to AAWP research!]. That's a lot of apps but, compared to the others, it's nothing more than a drop in the bucket.
You could classify this as a superficial interest, or as a missed opportunity for Microsoft. MetroUI is going to appeal to many users across various enthusiasm and skill levels - i.e. from power geeks to novices. However, some of those people are going to be Linux users, for which a WP7 device is next to useless.
Microsoft's core businesses are Windows and Office - and it will do anything to advance and protect them. However, is it really realistic to assume that people will switch desktop operating systems just for a phone? I doubt it - in which case, why isn't Microsoft doing its best to get its fledgling smartphone platform onto every desktop operating system?