I have heard from several sources that Hurley told the snowman joke last season, inferring that Hurley is the replacement Desmond is waiting for.
Can anyone prove/disprove this?

When Hurley was helping Jin with the raft, Jin was motioning to Hurley to make the rope (or whatever) tighter. And Hurley misunderstood and said, "You wanna make snowballs?". You know, typical Hurley smarta** remark.