I think Adolin will Be a skybreaker.
It is known that skybreakers have an innate ability to distinguish right from wrong.
adolin shows this three times, with Sadeas, Kaladin & Amaram. He instinctively knows that Sadeas & Amaram are not as they seem to be, and he knows that Kaladin is hiding something.
It can be said that shallan was hiding something too, but she was doing it on purpose while what kaladin was doing was not really working in his or anybody's favor.
The attributes of skybreakers are just and confident. I think Adolin is one of the most confident character we have seen. He is smart but not particularly intelligent, and it's the people with more intelligence & knowledge who are more doubtful (thus less confident).
While he broke the law when he murdered sadeas, but Kaladin strayed from his path too. And he hasn't formed a bond yet (not a complete one anyways), so it's not that big a deal. Maybe he will realise what he did was unjust which in turn will attract a spren.
Also, we can't take Nalan as an example of a true skybreaker, as his main goal is killing surgebinders based on small crimes which is rather unjust.
And Shallan's attribute is honest, while she is pretty good with lies, which attracted pattern in the first place.
As for him being a dustbringer, i don't see any evidence which supports this. he's not especially Brave or Obedient. Those can be said for Kaladin too (he jumped into the arena to save Renarin and Adolin which was brave, & he follows orders as much as Adolin).
But Szeth, who was selected by the Skybreakers, seems more Obedient than just, he Obeys, he breaks many many rules while doing so too. He seems more of a dustbringer than Adolin. Maybe Nalan just needed someone to kill a lot of people. And the bond he was talking about was his bond with the oathstone rather than the honorblade (i don't remember the scene clearly so not sure).
Szeth will probably end up doing the same thing as before, only instead of oathstone he will follow his God.
That was a little off topic, but i thought of it while i was writing.
P.S - Adolin also stayed in prison with Kaladin Because what happened was not right(just), that only Kaladin be jailed.
or he shouldn't have been imprisoned in the first place so he was protessting or something.