I agree that it's going to become more popular, but I also think that the term will lose it's social impact. As an increasing amount of couples realize that monogamy is an unrealistic proposition over the long term, people will just naturally slide into it.
Interracial relationships are becoming increasingly popular, both in society and within mainstream media. I can easily see open relationships following the same path. Where as you may see in a crime drama where the husband acknowledges that his wife with with another man and no one raises an eyebrow to the traditional SITCOM where the woman flounces out of the house, en route to see her lover.
It will probably follow the natural progression of white woman with white boyfriend, but over time, this too will morph into interracial fun.
Only time will tell I suppose.