Some people call "vendor sports" what I call it tea-leaf reading. I've been doing it for decades. I like to watch, and guess, based on incomplete information, what the various forces in the tech industry are doing.
A lot of times you can discern what big companies are doing, the same way astrophysicists discern the existence of black holes, by the effects they have on smaller more visible entities.
In this case, I think perhaps Twitter is getting ready to bust through the 140-character limit. Why? Because Medium appears to have given up on merging with them. How can I tell that? Well, because they went straight after Twitter, by introducing a timeline, and short Tweet-like messages, without the 140-character limit. This was Medium blinking. I was really surprised they did this. Up to that point I thought Medium was a juggernaut. That they were cleaning up. Apparently not. Apparently they needed to tap into greater growth potential. And if anyone is likely not to be overly respectful of Twitter's internal engine, it's the founder. He knows how the sausage factory really works, where the bodies are buried, etc. The stuff that we don't know.
I always thought Medium's manifest destiny was to be acquired by or to acquire Twitter (in the same way NeXT acquired Apple in 1997). The founder returns, bringing with him a feature that users are likely to adore. I said it this way: "There's a Medium-size hole in Twitter." I thought that was funny. Funny because it was so true.
I imagine, via tea-leaf-reading, that Dick told Ev, "Sorry dude, we decided to make vs buy, you want too much money, so we decided to build our own Medium clone inside Twitter." Much the way they said that Bit.ly wanted too much for their URL-shortener five years ago.
One way or the other. imho, the 140-char wall is not long for the world.
PPS: When will the 140-char wall come down? See this follow-up post.