Desmond will be the one who takes out Smokey MIB by Russ

ok, I believe that Desmond and his Electromagnetic powers are what will put the Smoke Monster/aka MIB back where he belongs.

you see Jacob accidentally released this smoke when he threw his brother down the hole.

He's never been able to find a way to get him back and therefore he was protecting the island and he was also bringing people back to the island so that he could complete this.

Desmond's abilities are what is the key to putting MIB back into the hole. putting everything back to order.

Jack is going to find Desmond, he's going to confront MIB at the right location and the reaction Desmond has will then change MIB and he'll go right back to the light.

Jack will basically be there to protect the island, much like Jacob was and like his mother..

It's pretty much a pattern.