I'm quite pleased with this new feature

dynamic-query.cs

     var ordersForCustomer = session.Query<Order>()
                    .Where(order => order.CustomerId == "customers/bob")
                    .TransformWith<OrderWithProductInformation, OrderWithProductInformation.Result>()
                    .List();

index.cs

        public class OrderWithProductInformation : AbstractTransformerCreationTask<Order>
        {
            public class Result
            {
                public string OrderId { get; set; }
                public string CustomerId { get; set; }
                public ResultProduct[] Products { get; set; }
            }
            
            public class ResultProduct
            {
                public string ProductId { get; set; }
                public string ProductName { get; set; }
            }
            public OrderWithProductInformation()
            {
              TransformResults = orders => from index in orders
											 let doc = LoadDocument<Order>(index.Id)
	                                         select new
	                                         {
		                                         OrderId = doc.Id,
                                                 Products = from productid in doc.ProductIds
                                                            let product = LoadDocument<Product>(productid)
                                                            select new
                                                            {
                                                                 ProductId = product.Id,
                                                                 ProductName = product.Name
                                                            }
	                                         };
            }
        }