Or at least it would seem so from the trailer:
The movie is about two women who are OMG BFFS forevs, until it turns out that they have to compromise about who gets to have her dream wedding at the Plaza. Instead of compromising (because deep down, women are just catty bitches who will take any excuse to sabotage their so-called friends, particularly when it comes to a pretty princess wedding.) [T]hey two duke it out for the single, perfect wedding that apparently only one of them is able to have.
Also see this selection of ads along the same theme.