Personally for me i don't find an issue in pretend play with 'weapons' - my girls watch barbie movies - they love the 3 musketeers and DD1 will pick up a stick and pretend to joust (sp?) with people, she will also pretend to protect her little sister from the bad guys.

She has water pistols and pretends to shoot people with them, to me it's just play - i grew up pretending to shoot & stab my brothers while playing pirates or whatever and i am not mentally deranged or running around killing people.

I think we need to remember that our children will grow up with the values we instill in them, if at an appropriate age we sit them down and explain what guns are for (hunting, protection etc) and that they are not toys and not for children to touch then we should be fine, if we hide them away & pretend they don't exist then they may get curious about them.
DP has his shooters licence, my girls have seen guns, we have showed them what they are and that they are not to be touched, they can be dangerous & they can hurt people, they are only to be used by adults and not near other people.
DP has never shot one near the girls and we don't have any of our own on the premises.

I know some people who have refused toy guns in their homes, no movies with weapons, no water pistols, no pretend swords for pirate outfits etc but their children seem to naturally have a curiosity - they build them out of texta's, they find a stick to poke at their brother etc etc.

I don't think there is a right or wrong when it comes to issues like this, it's what you believe & what your comfortable with - me personally it's all in explaining what these things are and what they can do - teaching my children about saftey around weapons and it's not about hurting people etc etc.