A lot of what I continue to read about graceful degradation applies to browsers that don't use JavaScript. But my own experience shows that it's no longer reasonable to expect a normal experience on the Internet without JS and CSS support. How much energy is it responsible to devote to degradation these days?
That really depends on your user base. If most of your users are lunch-time corporate visitor with js turned off then you should degrade. If you have a significant blind user base then you're best avoiding the rich interface.
Also don't forget about SEO and allowing bots to crawl through your site. For exmaple, if you're using a tabbed layout and the tab contents are only retrieved by a javascript ajax call then it's safe to assume that a crawler will not see it.
Check out this article from a list apart. It talks about progressive enhancement instead of graceful degradation. Instead of degrading the experience for users without a particular technology or users with accessibility issues, it focuses on starting with the basics (html) and progressing the user experience by utilizing what technologies the user has available.
With progressive enhancement you'll never need a noscript tag, since you don't assume the user has javascript enabled to begin with.