M15 (baseless speculation and spoilers)

[Remillo]

{Xenagos, the Reveler}, {Tezzeret the Seeker}, Chain Veil, {Voltaic Key} and six or more creatures.

Activate Xenagos for 6 mana, use the Chain Veil (2 floating), Activate Key to untap Chain Veil (1 floating), activate Tezzeret to untap Veil and Key.  Rinse and repeat, netting 1 mana and 1 counter on both walkers each time. 

And that's just from 20 seconds of thinking about the card.

Love it.

[Remillo]

{Xenagos, the Reveler}, {Tezzeret the Seeker}, Chain Veil, {Voltaic Key} and six or more creatures.

Activate Xenagos for 6 mana, use the Chain Veil (2 floating), Activate Key to untap Chain Veil (1 floating), activate Tezzeret to untap Veil and Key.  Rinse and repeat, netting 1 mana and 1 counter on both walkers each time. 

And that's just from 20 seconds of thinking about the card.

Love it.

And now my brain works correctly and realizes you don't even need the key.  In Standard, just go Xenagos, Ral Zarek, some creatures and Chain Veil and you get shenanigans

[Forbidyourways]

Wow The Chain Veil is amazing finally being able to use planeswalker abilities on opponents turns I love it

[Ace]

So I just realized, {ral zerik} + the new Nissa + the new veil artifact equals standard infinite combo! Take all the turns u want!

[Remillo]

Wow The Chain Veil is amazing finally being able to use planeswalker abilities on opponents turns I love it

Nooope.  Chain Veil is more akin to effects that say, like, "You may cast that card this turn."  You still have to obey normal timing restrictions, meaning you can still only activate the loyalty abilities when you normally could, so on your turn, during a main phase with nothing else on the stack.

[MuggyWuggy]

PW abilities on opponents turn = Kiora ultimate after she's out for one turn.

That would be stupid

[Forbidyourways]

You can just pay the 4 on there turn tap it and use PW abilities it doesn't say only on your turn

[Ace]

You can just pay the 4 on there turn tap it and use PW abilities it doesn't say only on your turn

Right, it says you may activate there ability. When can you activate a planeswalkers abilitys?...only on your turn as a sorcery. So there for you can only do it on your turn.

[Mattao19]

So you still have to pay it's loyalty cost right? Like you can't just ult a PW right?

[Ace]

So you still have to pay it's loyalty cost right? Like you can't just ult a PW right?

Correct, you still are using the loyalty points, the card basically is just allowing you to use your pw twice on your turn

[VQMracing]

We still have one land unspoiled, I wonder what it will be. It is something between {Darksteel Citadel} and {Llanowar Wastes} alphabetically. My money is on some sort of {Rupture Spire} or {Shimmering Grotto} variant.

{gaea's cradle} fits. Haha oh well one can dream:(

[Mattao19]

We still have one land unspoiled, I wonder what it will be. It is something between {Darksteel Citadel} and {Llanowar Wastes} alphabetically. My money is on some sort of {Rupture Spire} or {Shimmering Grotto} variant.

{gaea's cradle} fits. Haha oh well one can dream:(

{Karakas} DOES TOO!!!

[Forbidyourways]

For each planeswalker you control, you may activate one of its loyalty abilities once this turn as though none of its loyalty abilities have been activated this turn. So meaning this turn (opponents turn) cause your not using a loyalty ability on there turn you can the wording doesn't state only on your turn

[Remillo]

For each planeswalker you control, you may activate one of its loyalty abilities once this turn as though none of its loyalty abilities have been activated this turn. So meaning this turn (opponents turn) cause your not using a loyalty ability on there turn you can the wording doesn't state only on your turn

Compare it to {Chandra, Pyromaster}'s 0 ability, since it's the same basic principle.  It simply states that you can cast/activate the give thing until end of turn.  It doesn't say that you can bypass normal timing restrictions, so you can only activate/cast any time you normally could.  Now, it'd be different if it simply said "You may activate a loyalty ability of each planeswalker you control.", which would be more akin to something like {Memory Plunder}, since this allows you to cast/activate immediately as part of the resolution of the ability.  If the effect instructs you to do it right then, it bypasses timing.  If it says "Until end of turn", "This turn" or "As long as ___ Remains on the battlefield" ({Intet the Dreamer}), then you're bound by when you could normally use it.

Sorry if I'm incoherent, it's late and I'm tired and trying to explain things.

[Ace]

For each planeswalker you control, you may activate one of its loyalty abilities once this turn as though none of its loyalty abilities have been activated this turn. So meaning this turn (opponents turn) cause your not using a loyalty ability on there turn you can the wording doesn't state only on your turn

This is from the actual magic rules-

306.5d Each planeswalker has a number of loyalty abilities, which are activated abilities with loyalty symbols in their costs. Loyalty abilities follow special rules: A player may activate a loyalty ability of a permanent he or she controls any time he or she has priority and the stack is empty during a main phase of his or her turn...

The artifact ONLY let's you use the abilitys as though you have not done it this turn, effectively letting you use there ability twice on your turn. But at no point does it let you use the ability on the opponents turn.