Tera Beta is open to all.

Go to http://account.tera-europe.com and login or create your TERA account.
Follow the instructions.
Press the "enter code" button.
Enter the „TERABETA“ key.
Open your account overview.
Download the client.

I played in a previously Beta weekend, an enjoyable game but it didn't grab me personally.

What is this madness?

It's a new MMORPG, it was originally released in Japan and has now been "westernized".

The combat is cool, since you have to actually swing your weapon/shoot in the direction of your enemies.

This might be the MMO that a friend was ranting about to me once, although I swear he kept telling me it's Korean. All I really picked up from his ranting was that there's some area where you can build your own house, which at least sounds interesting.

That's Archeage.

Yeah I inquired about it and he said the same thing. Still this is taking an age to download at about 0.5MB/s.