User blog comment:JAlbor/Wikia at E3 2012/@comment-1192466-20120531100550/@comment-4814368-20120607061224

As expected, the team is tight lipped on all this. I will say that the team is committed to a single-player story-driven experience. I wouldn't expect Corvo related DLC on release. That being said, they spent too much time on world building to let the game sit idly between releases (presuming its a success). Again, this is all my speculation based on what I saw at E3, tone, etc.