The specific ballot language of the anti-gay amendment that voters will see on May 8 is:
 For  Against
Constitutional amendment to provide that marriage between one man and one woman is the only domestic legal union that shall be valid or recognized by this State.
Of course "domestic legal union" is not defined in the text of the amendment or in North Carolina law so it will be up to judges to define it if the measure passes, but it could most definitely be construed to mean that not only same-sex marriages but opposite-sex or same-sex domestic partnerships would be banned at the state level.
Since the vote is basically 2 months from today, the opposition to the measure has accelerated, with Scott Wooledge using a front-page post on Daily Kos to highlight the polls on the measure and promote the following video, titled "Momentum:
Let's work together to make sure that North Carolina's constitution remains free of the stain of homophobic discrimination on May 9 by donating money to defeat the amendment.