Siliconera reported that a new NieR trademark was filed on November 29th in Japan, but made public today.
Due to NieR (PS3, Xbox 360) 10th anniversary, Square Enix opened a website teasing some events and news. Many of us would love to enjoy a remaster of the first Nier game, and this could be the perfect moment for that. This trademark could be pointing in that direction and series producer, Yoko Taro, could have given clues about it.
However, there is another hypothesis: this trademark could just be Square Enix covering the entirety of the NieR series (Gestalt/Replicant, Automata, spin-offs) under one name.