The official PCG server has "gone rogue" as they put it and isn't working right now.
Uh, you know that on that very page of that issue you cited it tells you that though :P
Oh and there might be something to do with Bukkit as well but I'm not sure really. I've been dying to get onto the PCG server for ages too and it still won't let me and I don't know what the real server address is from the forums and the one in the mag doesn't work :'(
Also this thread explains better than I did and is from an official PCG dude.