Treyarch didn't allow much to happen to WaW. except .iso mods. which aren't even a big deal. I think if they release a beta, they're gonna make us happen and help themselves out. i don't think it will be very moddable, but this is too far in advance to say anything for certain.
I have never heard that it will have Dedicated servers... But I think that BO will be modded less than MW2. I think Treyarch is paying WAY more attention to BO considering how the CoD series contains more modders than any other game. Even though modding is fun, I hope there is less modding, but still SOME to make the game interesting
Put it this way new mods are found everyday and they have developed alot since the profile mods on cod 2 .ect and now we have systems that can run unsigned code who'd though that would happen? there will be improvements in mods and it will be harder but there will always be a way around and we will always be able to mod.