These forums haven't even been officially launched yet, however, some observant folks over at the VN Boards unofficial WAR forum noticed them and the word is starting to spread. It's pretty hard to sneak one past people on the Internet! You can log in to Warhammer Online's official forums with your WAR account username and game/account password (some people are reporting issues, so try using a combination of both).
Once logged in, you are prompted to enter a screen name and confirmation email. After setting that, you're good to go. Currently, the forum seems to be set up for the Public Test Server and 1.2 patch with subforums for announcement, general feedback discussion, RvR focus discussions, various combat and careers discussion, and bug reporting. This forum is embedded as a tab within their official WAR website. Mythic announced these forums a couple weeks ago, so it seems they are moving quickly on their word. We had a chance to speak with two unofficial WAR forum administrators from the VN Boards and Warhammer Alliance about how these official forums might impact their businesses. There was even some discussion surrounding things official forums can do that unofficial forums can't and vice versa. It's only a matter of time before we see how these forums will truly develop.