Nintendo held a Japanese Nintendo Direct conference for Monster Hunter 4 this morning which revealed that fans would be able get Mario, Luigi, and Link costumes and armor for themselves and their Felyne comrades.
Monster Hunter 4 has not yet been confirmed for North America, but it is releasing on September 14th exclusively on 3DS in Japan. Historically there has been a significant gap between Monster Hunter’s release in Japan and North America, so hopefully we will hear more about a western release soon.
According to a translation from Siliconera, the Mario and Luigi Felyne costumes will be through Japanese 7-11 stores. The Link armor, shield, and weaponry pack will be available as DLC.