And so far, that's what we've seen from Man of Steel villains Zod and Faora--but according to CBM, who found some costumes for sale online, it looks as though the suit of armor worn by Zod in the film includes a helmet with a full-facial mask...and a pretty gnarly one at that.
The odd contraption brings to mind the kinds of helmets worn by characters like Darth Vader and Star-Lord and seems likely to be something worn primarily during space travel or high-altitude flight, possibly as a breathing device (if this weren't all one piece and rubber, for instance, that bit on the bottom looks like it might be tubes of some kind).
So far, it's just kids who can see what their full, deluxe costume will look like; adult versions are available but there's no photo yet. You can check out a variety of Zod outfits at the Costume Craze website (that link will bring you to a search for the character's name).
Apparently there's also a wig? Hmm...
Update: Zod image removed by request.