Huge thanks to Allakhazam forum poster Tranquility for this find !

At long last, the 12GB Open Beta client is now available for download through our website. This download is open for anyone who is logged in at our website, but only Open Beta testers will be able to run the client. Open Beta testers include all current beta testers, Collector's Edition pre-order customers as well as customers who bought a Standard Edition pre-order via one of our premium partners. To download the client without Open Beta access will only slow the download for other users so we kindly ask you to respect this.

Please note: current beta testers will be able to patch their clients; no new download is needed if you already have one.

Get downloading folks!