I ran the hub like this and registered several browsers from different nodes.
java -jar selenium-server-standalone-2.0rc1.jar -role hub -port 9000

The following failed.
var webdriverjs = require("webdriverjs");
var client = webdriverjs.remote({host: "localhost", port: 9000});
client.init().url("http://some.host.com/");

And here is the console output.
[13:36:20]: COMMAND POST "/wd/hub/session"
NO DESIRED ENV {"status":13,"value":{"message":"Error forwarding the new session cannot find : {platform=ANY, javascriptEnabled=true, browserName=firefox, version=}","class":"org.openqa.grid.internal.GridException","stackTrace":[{"fileName":"RequestHandler.java","lineNumber":143,"className":"org.openqa.grid.web.servlet.handler.RequestHandler","methodName":"process"},{"fileName":"DriverServlet.java","lineNumber":79,"className":"org.openqa.grid.web.servlet.DriverServlet","methodName":"process"},{"fileName":"DriverServlet.java","lineNumber":65,"className":"org.openqa.grid.web.servlet.DriverServlet","methodName":"doPost"},{"fileName":"HttpServlet.java","lineNumber":727,"className":"javax.servlet.http.HttpServlet","methodName":"service"},{"fileName":"HttpServlet.java","lineNumber":820,"className":"javax.servlet.http.HttpServlet","methodName":"service"},{"fileName":"ServletHolder.java","lineNumber":428,"className":"org.openqa.jetty.jetty.servlet.ServletHolder","methodName":"handle"},{"fileName":"WebApplicationHandler.java","lineNumber":473,"className":"org.openqa.jetty.jetty.servlet.WebApplicationHandler","methodName":"dispatch"},{"fileName":"ServletHandler.java","lineNumber":568,"className":"org.openqa.jetty.jetty.servlet.ServletHandler","methodName":"handle"},{"fileName":"HttpContext.java","lineNumber":1530,"className":"org.openqa.jetty.http.HttpContext","methodName":"handle"},{"fileName":"WebApplicationContext.java","lineNumber":633,"className":"org.openqa.jetty.jetty.servlet.WebApplicationContext","methodName":"handle"},{"fileName":"HttpContext.java","lineNumber":1482,"className":"org.openqa.jetty.http.HttpContext","methodName":"handle"},{"fileName":"HttpServer.java","lineNumber":909,"className":"org.openqa.jetty.http.HttpServer","methodName":"service"},{"fileName":"HttpConnection.java","lineNumber":820,"className":"org.openqa.jetty.http.HttpConnection","methodName":"service"},{"fileName":"HttpConnection.java","lineNumber":986,"className":"org.openqa.jetty.http.HttpConnection","methodName":"handleNext"},{"fileName":"HttpConnection.java","lineNumber":837,"className":"org.openqa.jetty.http.HttpConnection","methodName":"handle"},{"fileName":"SocketListener.java","lineNumber":243,"className":"org.openqa.jetty.http.SocketListener","methodName":"handleConnection"},{"fileName":"ThreadedServer.java","lineNumber":357,"className":"org.openqa.jetty.util.ThreadedServer","methodName":"handle"},{"fileName":"ThreadPool.java","lineNumber":534,"className":"org.openqa.jetty.util.ThreadPool$PoolThread","methodName":"run"}]}}