One issue that I've seen raised from the fallout of whatever the ruling happens to be is that it opens a Pandora's box on the right to privacy.
Especially in regards to laws restricting travel across state lines (to use an extreme case), but you could also begin to see local law enforcement seeking court orders seeking information on people looking for emergency contraception or ever those seen near a suspected abortion facility.
What would stop authorities do the same in regards to guns somewhere down the line? While not completely restricting gun use, but gathering information on those visiting gun shops, gun shows, researching gun information on line?