There appears to be no way in the Flatiron stack to do a simple 301 or 302 HTTP redirect.
This should probably be added to https://github.com/flatiron/union/blob/master/lib/response-stream.js
To find any example of doing redirects in node, see: https://github.com/visionmedia/express/blob/master/lib/response.js#L529
Was thinking the same a few days back
Fixed by #36.