NO NO NO NO NO NO NO!
This just gives developers and publishers more reason to take weapons out of the game and put them back in as DLC. It's a horrendous idea.
Someone I saw the other day even said to put the weapons on the disc and then everyone can see them, but only those with the DLC can use them. That's a ridiculous idea!
And then what happens if you run out of ammo because you haven't got the DLC? "Oh no, I can't pick up this gun because I haven't got the DLC. I'm screwed!"
Not to mention the fact that it can completely screw up the balance of the weapons if it's not done right.
Awful. No way.
I think that weapon DLCs will be awesome! I think that it will help to keep people interested and if they bring out the AK74u like the one in Call of Duty 4 and not like Black Ops then it will certainly be welcome. Perhaps they could do a Call of Duty 4 weapon DLC which includes the M4 carbine and the R700/M40a3.