This episode will always be special for me as it is the one that was on when I visited Florida a few years back and so the only episode of the show I have seen outside of the UK. It brings back some great memories.
It's not the best episode in the history of the show but has some important themes running through it. I think it's safe to assume that the island did indeed heel Rose as she is still alive over three years later, which does indeed confirm the healing properties of the island/someone on the island!
It's been confirmed that Rose and Bernard will last until the end so I'd take it as a given that they will be back for the last season!