I think it's possible, probably a long shot now. If the group felt that they were going to secure 'a' NBA team in the near future they might continue. Arena's take time to build so this would avoid having to play at Key Arena for a couple years which was part of the original plan. I don't think it's likely anymore though given recent events. The immediate prospects for Seattle getting an NBA/NHL team are dashed given yesterdays relocation vote.
So at this point the arena is happening no matter what? I suppose that's a positive sign for the NHL's prospects in Seattle, although you'd still need an owner and, as fiesty said, the Hansen/Ballmer group won't be all that interested in trying to bring in the Coyotes (or any other team) without first having an NBA team in hand.
I do think think there is hope though, this guy was willing to up the ante $100m in the last week before a couple key votes, and he is trying to get a 20% share of the Kings. His ownership group is obviously very determined and that bodes well for Seattle.