Keep checking out the AX homepage, as well as the AX FB page and Twitter accounts for updates. According to what I've heard from Twitter, hotels will go up at the end of this month or early next month...but we'll see.
Just as a heads up, while AX may post rates for all of their hotels as a guideline, the last few years that AX has been in LA, they don't usually put all the hotels up for booking at the same time. They will start with the Westin Bonaventure (about a mile away from the convention center) and then after a couple weeks or so open up the rest of the hotels on their block. I've stayed in the Westin a couple times and it's a nice hotel, but if you can afford it, I'd highly recommend the JW Marriott as it's the closest of all hotels and it's also the nicest. But, it is rather pricey though