I've been playing pretty much only Jeskai Arcanist since WAR came out, and I think that in a shell with Mentor and multiple Pyromancers, Skullclamp has potential to be a valuable 1-of.
Skullclamp lets you replay Time Walk (and Merchant Scroll in a pinch) with Arcanist, and explode after making just one Monk/Elemental token. I had a game where I had only an Arcanist in play and my opponent (at 20 life) cheated in Emrakul and passed the turn. I had Time Walk in my graveyard and Skullclamp in play. I untapped, drew Mentor, and won on my Time Walk turn. Snapcaster or JVP wouldn't have worked here--I needed the insane card draw as well as the Time Walk.
In plenty of other games, I've gone turn 1: cantrip + mox + skullclamp, turn 2: pyro + cantrip, turn 3: draw 4-6 cards. It gets even better when you factor in casting counterspells.
These anecdotes shouldn't convince anyone to run Skullclamp, but I think the card merits testing.
As an aside, in a token-heavy list, Saheeli, Sublime Artificer may also warrant a look...