My team is working with a .NET 2008 DB Project in their solution so we have some way to persist the schema between machines and through development and keep things consistent.>
To update your projects's schema you can use "Schema compare" feature from Data menu. Choose your development database as Source, your database project as Target and get schema comparasion as result. It will find what you have changed since project creating and will show you diffs for tables and other database objects. So you will be able to look through these changes and skip some of them if you like. Then click "Write updates" and your changes are added to the project.