It's just a login to the community site, which is currently very quiet, and there's currently a demo mix video/course to watch - so you're not missing out on much.
I think they paused new user signups to the community area to fix some issues with the community forum software, and I get the feeling that they are pretty busy with the upcoming TC6000 release.
But I wouldn't worry about it too much, you're really not mixxing out on anything much at this time and I'm sure you'll be able to sign up in due course, when hopefully they being to add some more content and it gets a bit livelier... it's very new, and I expect they plan to build on it as time goes on.
