Unfortunatly WP7 will failed if Microsoft do not do a huge Adv campaign
iPhone and Android are flagged as "cool systems".
Microsoft one is microsoft... office, work...
So they have a huge job to do to become a cool device, the type of device the user will says "hey look at this, its cool and productive"
it will be hard to get a "wow" effect from the media and the consumers.
so I'm waiting for the advertising on TV to get my decision if this os is good or not. (sorry, the real capabilities become secondary today as all the OSes can do near everything)