I remember reading something about the obsidian dev's not being able to add content through patch's to console users... ( I think because of how they require disks to play )
So.. the only way it seems to transmit new content to console users is through DLC.. but we pc users have gotten
There is
no technical restriction to adding new content on consoles. Console users have been getting 'new content' since the day 1 patch, because of the way the game engine works. Let me explain.
The way Bethesda's gamebryo/creation engine games work is by loading .esp/.esm files. Skyrim is an .esm file. All patches are .esm files. Now... PC mods are ALSO .esm/.esp files... see the pattern? Basically, anything else other than Skyrim.esm is a mod, technically speaking. And anything a mod can do, the skyrim patch update.esm can do, and even more (since Bethesda made Skyrim after all

). And that update.esm file is independent of all platforms.
If bethesda added new content to the update.esm file, like killcams, mounted combat, ALL versions of skyrim, PC, PS3, 360.. would get it. That's just the way the game works. And you know what? The dawnguard DLC will be the same .esm format. Just like any other huge mod, only official.
The game that was released on 11/11/11 did NOT have the 1.1 patch file called 'update.esm' (the RTM version). But the day 1 patch (1.1) was immediately downloaded through steam, xbox live etc and immediately applied to the game. Basically every Skyrim users have been using at least one mod since day 1... and that's the update.esm file. This means that there actually aren't any restrictions about using mods on consoles, only Microsoft's and Sony's policies disallow them. Unless a mod explicitly depends on keyboard shortcuts or PC-specific features, almost all the mods released could be played on a console.