For what it's worth, I was able to download the initial data files (60GB or so) before the 11th of Jan, when the first wave of the Open Beta began. (I bought the cheaper Beta Pack before that for $30++ USD.) However, I wasn't able to update the game with the patch that was released on the day the first wave of the Open Beta began (11th Jan).
I suspect that they may have temporarily suspended access to the data files for anyone who doesn't have access to that section of the beta yet. In other words, second wave access should allow you to download all necessary files from the 18th of January onwards, and standard access / guest passes should allow you to download the files from the 25th of Janurary onwards.
Not sure if you can download the data files if you haven't purchased any of the game packs / haven't registered yet.