Although overshadowed by the picture of a forlorn Superman standing morosely in the rain, Zack Snyder actually tried to explain to USA Today why he chose a "V" for Batman V. Superman's title, as opposed to the infinitely more normal "Vs." It is the dumbest thing you will hear all day.
The director can't say exactly how the relationship between the two superheroes evolves, "but suffice it to say there is a 'v' in between their names" in the movie title", Snyder says. He explains that having the "v" instead of "vs." is a way "to keep it from being a straight 'versus' movie, even in the most subtle way."
The problem with Snyder's reasoning is that of course "V" still means "Versus." It's just an abbreviation that is used primarily for legal cases and nothing else. So despite Snyder's ridiculous effort "to keep it from being a straight 'versus' movie", he's still making a movie titled Batman Versus Superman, he's just done it in the most awkward way possible. Snyder isn't being "subtle" here, he's being patently incorrect.
Unless, of course, the "V" stands for something completely different that Snyder will reveal to us at a later date. Batman V(otes) Superman? Batman V(alidates) Superman? Batman V(ictimizes) Superman? I eagerly await your suggestions in the comments.
That wonderful image up top, by the way, is by Ali Arikan.