< 5% of users disable javascript

According to BrowserStatistics, in 2008, only 5% of users had JavaScript turned off. The trend has steadily been declining so it's very safe to assume that now near 2011, that number is much smaller.

Downgrade Gradefully

Your site should never be broken - no matter if the users have JS on or off. Even if it's as simple as displaying a message that your site needs javascript turned on, you should make sure that your website renders and behaves in an acceptable, non-broken manner for those select few.

Reworking for non-JS users? Normally: No.

The ordinary developer has no need to create a non-javascript version in another language. However, if it is known that your clients have anti-javascript needs, then you obviously are forced to cater to it. (Even GMail has a no-JS version)