ASP.NET Data Scaffolding Support (ASP.NET Dynamic Data)
.NET 3.5 SP1 adds support for a rich ASP.NET data "scaffolding" framework that enables you to quickly build functional data-driven web application. With the ASP.NET Dynamic Data feature you can automatically build web UI (with full CRUD - create, read, update, delete - support) against a variety of data object models (including LINQ to SQL, LINQ to Entities, REST Services, and any other ORM or object model with a dynamic data provider).
SP1 adds this new functionality to the existing GridView, ListView, DetailsView and FormView controls in ASP.NET, and enables smart validation and flexible data templating options. It also delivers new smart filtering server controls, as well as adds support for automatically traversing primary-key/foreign-key relationships and displaying friendly foreign key names - all of which saves you from having to write a ton of code.
You can learn more more about this feature from Scott Hanselman's videos and tutorials here.
ASP.NET Routing Engine (System.Web.Routing)
.NET 3.5 SP1 includes a flexible new URL routing engine that allows you to map incoming URLs to route handlers. It includes support for both parsing parameters from clean URLs (for example: /Products/Browse/Beverages), as well as support to dynamically calculate and generate new URLs from route registrations.
This new routing engine is used by both ASP.NET Dynamic Data as well as the new ASP.NET MVC framework. It will support both WebForms and MVC based requests.
ASP.NET AJAX Back/Forward Button History Support
.NET 3.5 SP1 adds new APIs to ASP.NET AJAX to allow you to better control the history list of a browser (enabling you to control the behavior of the back/forward button of the browser).
ASP.NET AJAX Script Combining Support
.NET 3.5 SP1 introduces a new
The script combining feature supports both path based scripts and assembly resource based scripts, and dynamically serves up the combined scripts using the ScriptResources.axd handler.