Cocktail v0.5 is available for download

• Domain model objects: This is not new. The difference between an entity and a value object is that an entity has an identity. The data of an entity can change over time, but its identity never changes. For example a person can change their name, move to a different address, but it's still the same person. A value object doesn't have an identity. When the value changes, it's a new object. For example '$2' is a value object. It has a currency and an amount. If you change it to '$3' it's now a different object.
• Factories: Factories create new domain objects. As you can imagine, creating a new domain object could involve multiple steps. For example in TempHire, creating a new StaffingResource involves three steps and additional data needs to be retrieved from a repository in between. Over time you can imagine that we may have different types of StaffingResources and each one involves different steps to create it.
• Repositories: As opposed to the simplified approach, repositories don't save. The main responsibility of a repository is to retrieve domain objects from the underlying data source. It becomes more obvious why this is important when you have multiple repositories participating in a workflow. Which repository should save the changes at the end? The answer is none.
• Services or Domain services: Domain services contain stateless business logic that is performed on the domain objects. They use factories and repositories to implement a particular process. For example transferring money from one account to another. Such a transfer service could use the account repository to retrieve account 1 and account 2 and then modify both accounts accordingly. TempHire currently doesn't have any domain services.
• Unit of work: The unit of work brings all the above together. It represents a single workflow instance within your application. It's main responsibilities are tracking changes and committing (saving) or rolling the changes back at the end. This answers the question of who does the save at the end of a workflow. Thanks to DevForce, implementing a UoW is actually very easy, because the EntityManager already does most of it. The UoW also exposes the Factories, Repositories and Services correctly configured so they can all participate in the current workflow.

Hope this helps.