the attraction in worms 2 was the fun weapons. there is no requirement to use all the weapons at your disposal, and you can be very effective with just bazooka (DBW cannon equivalent). But it makes the game fun.
DBW will get boring with just the same weapons, there's only so much you can do with a fountain.
I think there's a lot to be said for the current weapon balance. For those who want cannon-only, it's there. Personally though that would take a lot of the fun out of it for me, grenades and mirvs have excellent tactical uses, and they are NOT no-skill weapons in any way, shape, or form, I don't know where that idea came from. The fountain can be a little bit of a "no-skill" weapon, but that's why you only get one of them, and you still have to get pretty close to do any damage, it's not like an ion painter or something.
The problem I have with more weapons is that most ideas seem to be the "no-skill" weapons that DavidM was talking about. Straight-fire weapons are uneccesary - a good play will have 99% proficiency at getting a one-shot kill with a cannon on a player close in and in plain view.
I don't know if this has been mentioned already, but I found a bug in Warfare with the grenades. Sometimes if I throw a grenade and manages to come to a stop on the ground without touching anyone (usually a result of a very long fuse), the countdown on the grenade timer stops and we have to reset the server. This happened twice in different games.
just some ideas. rens already knows most of this but i'm bored so i'm gonna write it here too. Naturally some of these options are down to mappers too.
teleporters/portals
health packs
kamikaze
water filled areas as natural divides
ability to build small local objects eg screens... need to be destrucible maybe
replay facility for shots that take over x damage or more than 2 kills
weapon modifier eg high bounce/low bounce