I think they Isles will impress next season. Their goaltending is shored up now, they have a lot of talent up front and some emerging stars on defence as well. Sure Halak isn't in the top tier of goalies, but he isn't being paid in the $6-$7 million range like Quick, Price or Lundqvist. He's had solid numbers and stabilizes their goaltending for the next few years, which is a luxury the Isles haven't had in a loooooong time. Look for them to add some pieces on defence in free agency. You'll notice they didn't defer the pick they owe to Buffalo to next years draft (which is really deep...) until after they had Halak signed (well, same day, but you have to think they knew it was pretty much done when they deferred the pick).
The Islanders clearly think they're a playoff team with solid goaltending and a healthy Tavares. Heck, they were in the race this year without decent goaltending until Tavares went down at the Olympics. They're in a similar position to the Jets, except the Isles have made moves to improve their goaltending (sorry arby...) They've got some young talent and should be better than their standings show, but they give up too much in the way of shots and high quality chances. That's where a solid goaltender can really bail a team out. Pavelec hasn't cut it in Winnipeg, nor did Nabokov last year for the Isles, and both teams fell out of the race and missed the playoffs. Halak is an upgrade.
They may or may not make the playoffs, but I believe the Isles will be better next year, and at least be in the race down the wire (assuming they stay healthy). Snow and the Isles take a lot of heat, but I'd like to see them succeed and prove everyone wrong.