Capcom announced on their Twitter page that the next MH 4 U DLC pack will be downloadable on September 4th.
New #MH4U DLC comes out on Sept 4! In the meantime, make sure to get the August DLC http://t.co/6vmMhn8EMD https://t.co/uFTsVzxCgp
— Monster Hunter (@monsterhunter) August 25, 2015
The quests, armor or extras included in the September DLC pack have not been revealed, however. On the other hand, Capcom has said that the GX armor is going to be part of this DLC, as teased in their August 7 blog post. The GX armor set has only been craftable in the Japanese edition of Monster Hunter 4 U and is desirable for each piece having three slots for adding charms/ decorations to add skill levels to the armor. The August DLC pack included 10 new quests, 4 challenge quests, 1 bonus palico: Purple Pal, 1 guild card background and 7 new Guild Card titles. If you just picked up a copy of MH4 U, the March, April, May and June, July and August DLC packs are available to download for free. To download your packs, speak to your housekeeper in your house. The DLC packs are only able to be downloaded once. Once Capcom announces the contents of the September DLC pack, we will post it right here at BagoGames! Source: Capcom (via Monster Hunter Twitter Account)