I think it's a good possibility the Hurley Bird will remain at least partially unsolved. It just doesn't seem important enough to devote a lot of time to. I imagine it will be explained as it relates to the larger mysteries of the island. That being said, I wouldn't be upset if more time was given to the bird and its explanation, I would actually really enjoy it.
On a similar note, I'm desperate to know what the deal is with the statue, who were the folks who built it etc. This mystery has fascinated me because it seems no closer to being answered, whereas other things (The history of the Others and Dharma) seem to be coming into focus,albeit slowly.