Ireland's already independent.. Just perhaps not all of her ;)
The sad thing about the possibility of a real debate is that those proposing the unification still have literal blood on their hands. The conversation morphs from those proposing unification to being about those proposing the idea, and how they've been involved in horrific violence not-so-many years ago. The point of the debate is lost in the mire from that point on.
I believe it'll take a generation removed of the troubles to be capable of grasping the possibility. But I would LOVE to be proved wrong!