The game is currently in beta, and available for download and play by anyone.
The release date is March 19th and will be dubbed Runes of Magic - "Rise of the
Demon Lord"; take a look at the official post:

After three months of intense testing and gathering tons of feedback from our
community, the Runes of Magic Open Beta is now on going into its final phase.
We are proud to announce that on 19 March 2009 we will officially release
Runes of Magic - Chapter 1: "Rise of the Demon Lord".
Until then we will add many more features and new
content to the game and are looking forward to welcoming thousands of new
players to Taborea.
Get more info on the official
RoM Website.