On stackoverflow I can't click things that have JavaScript-functionality, like answering, upvoting, commenting and so on. Preview of a new question is also not working, it's just like if JavaScript wasn't enabled or if an error in the JavaScript code prevents everything from being executed. Only editing works. So I can't comment your answers on this ticket, too - weird...
I checked this in Opera, Chrome and Firefox (in Firefox it worked for about 2-3 pageviews, then stopped working), and everywhere JavaScript is enabled (it's really enabled, and no plugin interference). Firebug in Firefox doesn't throw an error.
It doesn't work here or on serverfault.com either.
UPDATE (since I can't reply to comments): It's totally weird.. I emptied the caches, and called this page in IE8 where I never visited stackoverflow.com (or meta) before. And it doesn't work here, too....
Ctrl
+F5
first to make sure all the Javascript is up to date?