It's not confirmed yet that it will be a remake of the original anime. I hope it won't be an adaptation of one of the spin-off mangas, like the "Raoh gaiden ten no haoh" anime, since they're average at best. I personnaly think it will be a new story, like in the 2000's OAVs named "Shin hokuto no ken". But i would'nt be surprised it's an adaptation of the rei gaiden, or the toki gaiden.