Exchanging data

You are designing a new application that stores data about weather conditions throughout the world. Your business model relies on selling this data to customers so they can use it in their own applications. You use a relational database to store your data, and you access your data through web services that can be accessed by authorized users. You also create regular XML dumps for users that want a local copy of the data.

What are the advantages and disadvantages of using the Entity Framework?
Which techniques do you plan to use for your web services?
How will you expose your data as XML?