Actually, the problem isn't Twitter per se, is that we've found out it's easier to digest (and regurgigate, and fabricate upon) 140 characters at a time. Twitter has inadvertently found an incredible exploit and vulnerability of the human mind, and now it's out there and we're fucked, excuse the French.

Even if Twitter were to die tomorrow, my conjecture is that most of the news and media will move to some other form of short-and-easy-and-dumb social network. 140 characters is what the TV was to the radio.

The comparison with radio => TV breaks down when you realize that TV is a medium much richer in information than both 140/280-character text and radio. (Of course Twitter is not just text these days.)

But anyway, I'm much more concerned about not so much journalists themselves, but rather about those people that are still trying to have discussions on Twitter. Starting with politicians, for obvious reasons.