I haven't kept up with the expansion draft rules to know for sure, but don't we have to expose a certain amount of dollars in the expansion draft? I would think the logical choice would be to expose Smith for the expansion draft, if he doesn't have a bounce back year and even then I'm not sure it's worth keeping him long term. If this season is basically a flop then you expose Smith to Vegas and hope or work out a deal to get them to select him. If all else fails then you could consider a buyout after that. Even then you could argue holding onto him for one more season may be worth it for that expansion draft and all of the same conditions.
A lot really depends on how well this season goes and the direction of the team. Maybe Domingue gets more time this year and looks more like the last half of his season (6-12-1, ~2.8 GAA, .908 SV%, 0 SO) than the first half (9-6-4, ~2.6 GAA, .914 SV%, 2 SO). If that happens, there are still issues in goal. At his best last season (first half) Louie was statistically the same as Smith, but I think we all agree that if we can get that kind of goaltending consistently this team could be a playoff team.