Remember in NYC you already can't have a pistol unless you are connected, can't have an assault rifle and have to jump through a lot of hoops to have a longgun.
I suspect that in urban/suburban areas in the more liberal areas of the country i.e. the west coast and northeast, pistols may be impossible to get permits to carry & "assault rifles" will be outlawed. I don't think there will be attempts to take away guns, but if you don't already have them you aren't going to get them. Eventually those of us who have them and grew up with them will die off.
None of my sister's children (ages 8-16) have ever seen a real firearm, except maybe a policeman's pistol, and certainly never fired one. They have grown up in the suburbs with their playtime centered around sports-soccer mostly- cable tv, video games, the mall and the computer. None of them have probably ever spent a whole night in the woods and maybe have never even seen a night sky with no background man made illumination.
I suspect the next step will be restricting the ownership of semiautomatic firearms but lever action, bolt action, pump guns will not be restricted outside of NYC/Boston/LA/SF in the next 100 years.
I would also bet on bullet taxes, EPA regulation of outdoor firing ranges, the nipping away of areas where one can carry a gun (i.e. bars & government buildings first, then churches schools malls) until carrying is too great of an annoyance to bother with.
Don't worry tho, hopefully by then I will have my island in the tropics and you can all come shoot there. [:D]