The AHA actually commits to the purchase of blocks of rooms at several hotels. This allows us to bargin for better rates on both hotel and convention space. These rates are typically below the going rates for the hotels.
This is an important part of setting up a conference. For GR we have commitments in multiple hotels and, I'm sure, will be looking for more.
My suggestion is to wait for the NHC conference block to be opened, my GUESS, is sometime in February 2014, but it is way too early to say exactly.