I can connect fine, so it's not a serverside issue. Has the problem fixed itself or is it still occuring? Have you added any new firewalls etc to your setup? Virus checkers? If you reinstalled or updated the game you may need to re-authorise the game EXE to connect to the internet.
I think something in your system (Windows / firewall, anti-virus software, router, etc) was blocking the game from connecting to the internet, so it couldn't even reach the lobby system. If you modified the game files or updated the game EXE many anti-virus programs will decide that the software may have been changed and block it from connecting to the internet. Deleting the game and re-installing would usually reset this.