In this passage, what is being spoken of is "law". This is NOT a New Testament decree regarding divorce and remarriage, but rather it was Paul talking about the law of the time. Husbands were allowed to divorce their wives, somewhat easily might I add, under the law -- but women were not afforded the same privilege.
This is also a good example of taking scripture OUT OF CONTEXT. If you take the time to read the verse that comes after these verses, you'll find that:
"[4] So, my brothers and sisters, you also died to the law through the body of Christ, that you might belong to another, to him who was raised from the dead, in order that we might bear fruit for God.
They are talking to the Jews about transitioning from their old traditions, to Christ.
The verse doesn't imply that someone can't marry another person, but it is actually saying that they CAN marry another person because these laws are NOT the laws of Christ, plain and simple.
Verse 1 stated "Do you not know, brothers and sisters for I am speaking to those who know the lawthat the law has authority over someone only as long as that person lives?" and then we have the passages above, and then verse 4 states "So you also died to the law through the body of Christ"
In other words... the law no longer applies. I wish people would realize what these things are actually saying based on context.