Absolutely nothing. He will look like the Edmonton Duby. He plays decent in a defensive first structure, and with Burns and EK on the ice, that just isn't happening. Best of luck to him and I hope he proves me wrong, but my expectations aren't high.
Most of the attempts I have seen to isolate goalie performance from team defense in a statistically rigorous fashion suggest that, in fact, Dubnyk has actually been quite poor overall for at least the last three years.
Of course goaltending is voodoo and who knows what will happen, but I strongly suspect that if there is anything somewhat resembling a full season in the works, Dubnyk is going to get completely ventilated.
I honestly think that they would have been better off keeping Dell.