I feel like rushing the DLC would mean missing out on quality. I'm truly hoping Bungie is working really hard on the Dark Below to make it as worthwhile and full of content as possible in order to appease the players complaining about a lack of content. If I have to wait 2 months but get an expansion that is really worth the money I will be extremely satisfied and I would guess that Bungie would earn back a good portion of players, more than would be gained by quickly throwing together the DLC and getting it out early to try to get players back as soon as possible.