I finally gave Mastodon a try because many interesting Twitter accounts I follow moved there, or at least got active on it and broadcasted the fact. I have to admit I am positively surprised so far. Very much so.
Now everything depends on how much activity remains once the current dust settles.
Will Mastodon overtake Twitter? I still doubt it, but honestly I really can't imagine why I would care about that as long as Mastodon manages to establish, nurture, and retain a healthy userbase. Which is all I would need to keep using it.