Yup, in Mahwah area, up Route 17 near the NY border. The NYSE built a massive data center there specifically for colocation of high frequency trading operations, even going so far as ensuring each customers switch runs are the same length. It was on 60:Minutes a while ago.

The main NJ data centers for exchanges include Secaucus (Equinix NY4), Weehawken (Savvis), Clifton (Telx), and now Mahwah. All of the major stock exchanges and some of the options exchanges are in one of these data centers.

If I've left any out, please feel free to add as a comment.