I think they originally planned to have just 10 episodes this season, but after Adult Swim bumped it to 16 they broke it into halves. (Or it sounds better to say it's one season of sixteen than to say it's one season of eight followed by another season of eight. Or it'll sell more DVDs. I can't seem to find the quote at the moment)
Whatever the situation, new episodes can't come soon enough.
ROLL CALL: SUPERMAN! LOIS LANE! TESS MERCER! THE GREEN ARROW! CHLOE SULLIVAN! Special DC Universe Guest Stars: EMIL HAMILTON! AMOS FORTUNE! With Special Mentions of: ZATANNA! BATMAN! WONDER WOMAN! And possibly: BEPPO THE SUPER-MONKEY!