Obamacare is already heading back to the Court.
http://www.westernjournalism.com/obamacare-headed-back-to-supreme-court/
http://www.breitbart.com/Big-Government/2012/11/26/SCOUS-Reinstates-Obamacare-Case
So we could have a similar situation, where the Court issues one ruling affirming the act of Congress (i.e. making it law) but gutting certain provisions of it.