OK!

After @Matthew pointed it out to us, I've gotten in contact with @AhmadMetallic about the GiantBomb mumble server he admins and he helpfully agreed to set up a Guild Wars 2 channel on it in light of the coming beta events.

For those unaware, I've quoted the information on the server below;

:: Giant Bomb Voice Server ::
We have a 100-slot Mumble voice chat server for Giant Bomb, you're welcome to hop on, invite your friends, and use the many game-specific channels to converse as you play or simply chit chat with other giant bombers!
The server is available 24/7 and it's open for everyone. Don't hesitate to use it.
I'm the administrator of the voice server, so if you're having any issues, you can ask here or PM me, or talk to me on Steam.

1. Download the Mumble client here and install it.
2. Open the program, you will get a window asking you to connect to a server. Click "Add New...", and type in the following:

• Label: Giant Bomb
• Address: ny.eoreality.net
• Port: 64747
• Username: [Your username].

3. Click OK and then Connect. When you get prompted for a certificate failure , just click Yes. You will now be able to connect.
4. Right click on your name when you're on the server and click "Register." This will assure that no one else will use that name.

So, for the foreseeable future, assuming there are no outright problems with it, we'll be using this mumble server for guild events and general chat. If our guild grows too large (which I somewhat doubt, to be honest), then we will spring for a dedicated server. Until then, I think this is a great solution - so thanks again to both mat and ahmad.

See you online!

This makes me feel all warm and fuzzy inside. I like personal communication! Typing is so slow... 

I will add this info to the OP in the guild post.