During the usual Bungie Weekly Update, the company let slip the following screenshot:
As you can clearly see, the gamerscore shows 1250, instead of 1000 and lists 59 achievements instead of the current 49. Bungie says they have something special planned for October. It seems pretty obvious that this something special will be a new DLC pack. Considering Halo 3 has a total gamerscore of 1750, and a whopping 79 achievements! Needless to say it doesn’t take a genius to realize Bungie has big plans for Reach.