Davey Wreden, the writer for The Stanley Parable, tweeted out that he is writing an announcer pack for Dota 2. We don't have any more details on it right now, but just the fact that it's coming is enough to get me excited.
I love DLC like this. It's simple and fun, and it adds something interesting to the existing game. I would much rather buy a narration pack than a gun of +1 rampage.