It wasn't written for the janitor at Twitter, rather it was for people outside Twitter who want to think about what might be coming next. Yes, it is obvious. The idea was taken straight out of Facebook. I thought people would benefit from seeing what it would look like in action. As developers it's easy for us to imagine it, but even we need to mock things up to get a look at it, to help think better about it.
i think my main point is that the display mechanism must be the least of the concerns with respect to introducing > 140 characters. that is to say- I don't believe anyone thinks it's an aesthetic impossibility.
it seems fruitless to dictate "how" without being part of the "why and why not" discussions.