Why the Little Sisters of the Poor should win in the Supreme Court

The U.S. Supreme Court recently agreed to hear a challenge by an order of Catholic nuns, the Little Sisters of the Poor, to a federal regulation implementing the Affordable Care Act's (a.k.a Obamacare's) contraception mandate.
Is the Little Sisters' case likely to succeed? I'm not sure, but the Little Sisters do seem to have the better of the argument. (Would that having the better argument were all that matters at the Supreme Court).