The following comes up on a bunch of my indexed pages:

"Hello, you need to enable JavaScript to use this network. Please check your browser settings or contact your system administrator. ... "

Should I be worried?

Search engine ranking probably isn't the first thing to be worried about on pages that require JavaScript. Whether or not you should be concerned depends on what your pages are intended to accomplish, their audience and what the indicated JavaScript does.

Estimates of the number of users running with JS disabled range from 10% to 25%. That can be a significant number for a commercial site, so you may end up turning business away if you require JS for functionality. There are also issues with accessibility, as JS can interfere with screen readers and other adaptive technologies.

With the advent of "Web 2.0", more sites are requiring JS to deliver core functionality in their pages. The trade-off is a reduced audience for a slicker presentation. You must decide which bests serves your purposes.

In terms of search engine ranking, I doubt you have much to be concerned about. In terms of site usability, well, that depends.

remember always: JavaScript is NOT Java.