The GlassFish website has been down for a number of hours (together with a number of other projects) as a result of a general outage in the java.net datacenter. The team is working hard on getting everything back to normal. You can track progress by following @ProjectKenai.
Update: services should now all be back to normal. If you face java.net issues in the future, consider reporting them here. And now, back to work!