Gauntlet, Götterdämmerung, Havoc, and Tiburon are probably my top four most expected, but not yet announced yet units. Anzu, Carronade, Mongrel, Scourge, and Quasimodo are also models I'd lie to pick up.
I also wouldn't mind some of the Vehicles (Schildkröte being a major one) and BA, though I know BA is going to be unlikely without more fan financing style of stuff