The whole release was very user unfriendly. But I guess it's beta, I spent a while finally getting into a server. The server viewer just reports an error getting the server list. I have no firewall on my computer.
The only way I could get in is by (because I know the UT3 menus) switching it to windowed mode because of this and then doing the join game, F10, open "IP" trick.
The gameplay itself was pretty impressive. I liked it. But yeah, the way of getting in annoyed me.