John Piper doesn’t think so. He writes:
Tweeting is to preaching what the book of Proverbs is to the book of Romans. It’s the difference between epigram and argument. In fact, if you need a biblical warrant for the literary form suitable for Tweeting it is the book of Proverbs.
I think Piper is on to something. Brevity is not the enemy of thinking. What might be worth pondering further is what is the enemy of thinking. Whatever that enemy is (for it could be different for many of us), that is more dangerous than a communication tool that constrains us to 140 characters.