Pros:
Great build quality, unique design and perfect size.
Xbox Live
Microsoft specific software
People hub? even though i like to use individual apps for twitter and facebook.
Email - it has the best email experience for exchange compared to iOS and Android.

Cons:
Low res display
Ecosystem non existent and most 3rd party apps performance is really horrible. (although this is improving slowly)
Camera is bad and i expected more on this from Nokia. This is in comparing to 4s and high end Samsung phones.

Wrap Up:
Overall it's a decent device if you are not using lots of apps and just use facebook, twitter and some major apps. It is a great device for someone who just want's some basic apps and an easy phone experience. WP ecosystem lacks lot of major apps and doesn't get all the new hot apps immediately. I would wait for Windows Phone 8 devices before i consider them for my daily use.