try browsing half the web without JS enabled and it'll look just as bad
The most recent data I could find (2010) puts it at around 2% in the US. I would venture that 2% should be considered uncommon.
http://developer.yahoo.com/blogs/ydn/posts/2010/10/how-many-...
Another thing to take into consideration regarding this sort of stats is the user base. I _think_ a lot of the NoJS (or the likes) users are of the tech-savvy bunch and more likely to use sites like this one. So, I _think_ a more relevant percentage of people that have JS disabled is higher in this case.