For now, you can visually debug using node-inspector. You'll have to install nodejs and node-inspector...
The httpd server now accepts -d on the command line to enable debugging. Instead of pre-forking, it enables the debugger and calls HttpChild.run().
Run node-inspector from a second command line, after starting httpd-silk.js with the -d switch:
mschwartz@presto:~/src/othello$ node-inspector info - socket.io started visit http://0.0.0.0:8080/debug?port=5858 to start debugging
Now point your webkit browser (e.g. Chrome) at the URL printed by node-inspector. You should see something like the Chrome Dev Tools window in your browser. The scripts tab will show all your server-side scripts. Breakpoints work, etc.