Windows Phone 7 is nearly a year from being reality but Steve Balmer announced the new platform (software and hardware) at the Mobile World Congress in Barcelona today. If you have not yet watched the announcement, and have some time on your hands, it is worth watching.
In my opinion, Windows Phone 7 represents a dramatic change, potentially unifying your various personas (work, personal, etc) into one interface that looks to be a nice evolution of the iPhone interface. It is part Social CRM, providing you with a 360 degree view of your contacts. If Microsoft is smart they will weave both Microsoft Microsoft Dynamics CRM and Mirosoft SharePoint throughout the experience. Both software platforms, delivered from semi-private clouds, would give them a strong edge with business users and the Enterprises they work within.
Windows Phone 7 should be available on phones by the holiday 2010 season. In the mean time, check out the pros and cons from Eric Zeman at InformationWeek. He nails the pros and cons well and I recommend giving it a read.