TNT/AMC/FX/SyFy have been known to forgo the pilot process and simply order a run of a series, usually 8 or 10 episodes, then, they'll show them all and let ratings determine their future. Walking Dead started life as a limited 7 episode run and look where that's gone. Franklin and Bash have been done so far in two 10 episode seasons. Similar for Falling Skies. We probably won't know until it goes on the airing schedule.