Roman Josi is the comparison that TSN bandied about. For me I think his offensive skills are still developing - he's never really been take off the leash, whether that's by his coaches or by his own focus - I could see him being a better player on the rush and coming out of the zone than Josi at the NHL level. Which is really saying something as Josi is going to be an annual 35-40 point player on a defense first team.
I think that he already has just about everything you want for an NHL Dman these days - size, skating, hockey sense, strong in his own zone, great first pass, patience, can play PP minutes (though not a true PP QB).
The only thing lacking is that nasty edge - but that doesn't mean he isn't physical. He will play the body and use his own strength in his own zone, pinning players against the wall and hitting. He's much more physical than Josi in comparison.
Let's not forget that he also played on a very poor team talent wise - Could turn out to be one of the top 3 or 4 Dmen in what was an extremely strong class.