It'll probably be either Soul Eater or FMA. Higashi is too short, and its plot, though excellent beyond words, is incomplete, at best. There's still two more movies for the series, and we have not meet all of the Selecao yet. Higurashi doesn't seem like an Adult Swim kind of show. The main problem with it, is the "power of friendship" anvil at the end of the last two episodes.

Adult Swim doesn't do like that.