We've tested our latest build, and all critical plugins are up and running. Please update your client. There are a few minor bugs, but they will not severely affect game play and will be fixed shortly.
The reason we are still running 1.6.4, rather than 1.7.2, is because it is still insecure, buggy, and it would break several of our plugins. We will only update the server to the public once everything is stable.