Just in time for folks taking the Thanksgiving week off to catch up on coding that Silverlight app they've been dreaming of.... there's an updated Silverlight 1.0 SDK to get you started.
For folks with existing Silverlight applications it's worth grabbing and updating your Silverlight.JS as it has an improved first-time install experience as well as better performance (which is always welcome).
Grab it from the November Silverlight 1.0 SDK Download page.