Whilst playing SC2, it is revealed that the Artifact interacted with Zeratul's crystal in a way that caused Hanson to believe that the Artifact would drain the life out of a Protoss if activated in the presence of one. Now, why would Blizzard add this little detail if they didn't plan on revisiting it some time down the road? Well, Blizzard seems big on turning incidental background information into major plot points in subsequent expansions/sequels ever since WC3; which in turn leads me to think the Artifact will play a major role again later in the story.
My theory is that someone (and my money's on the Dark Voice/Hybrid faction) will use the Artifact on the Protoss, causing them to be further forced into the brink of extinction. This actually works well with the current speculation that Narud is actually Duran in disguise. After all, he's part of Moebius Foundation and so well aware of the search for the Artifact and probably its plan to deinfest Kerrigan. And if Narud is Duran, why would he go along with it? Unless, of course, it's a cunning gambit in which he trades Kerrigan (and so control of the Zerg) in favour of a device that can wipe both of them out en masse.