What are "Dynamic Live Lists"?

This refers to in-memory lists that automatically include business entities based on rules, removing the need for the developer explicitly to add new or modified entities to the list.

The collection navigation properties generated for business entities by the Object Mapper are live lists; e.g. aCustomer.Orders always returns all of the Orders associated with aCustomer. You can add a new Order entity; associate it with aCustomer; and it will automatically be included in the set of orders returned by aCustomer.Orders, without your having to add it that list.

You can also define custom EntityListManagers where you specify the rules; e.g., you could define a list, myList, that you want to include all current-month Orders for Customers a, b, and c involving Products p, d, and q.  Instead of your having to add the appropriate Orders explicitly to MyList, you define an EntityListManager, myEntityListManager, tell it to manage your List myList, tell it what the rules are, and then relax and let it do the work.

If by any chance you use iTunes 8-), the difference between regular lists and live ones is like the difference between Playlists and Smart Playlists.