According to various sources, including 2ch, mixi, and Moonphase, Higurashi no Naku Koro ni Kai ｢ひぐらしのなく頃に解｣ will include the following arcs — (in order):

The new 24-episode Studio DEEN series begins airing later this summer (July) …

Source(s): [1], [2], [3]