Battle for Zendikar introduced a game changer for Magic in the form of Zendikar Expeditions. These rare forms of powerful lands added a new level or rarity to booster packs in a slot technically for reprints, though that was unique enough to be sought after.
Expeditions were a rousing success, and the excitement around them was palpable. Unsurprisingly, WotC is looking to emulate this success, and a similar line has been announced for all Standard sets for the foreseeable future. Introducing the Masterpiece Series:
The Expedition analog for Kaladesh's Masterpiece selection will be called Kaladesh Inventions, and the lot of them can be found in their visual gallery here.
If you look over the prices of the Standard legal Zendikar block, you'll notice that Expeditions have caused a significant impact on prices for what you would expect for a Standard legal set. The Expeditions are sought after, and their high price tags soak up a lot of the value from the set, which has the effect of making Standard a cheaper format. This makes it difficult for regular rares to be worth much of anything, though some mythics are still able to command higher price tags. Notably Gideon, Ally of Zendikar has consistently held close to a $20 price tag, though the "Expedition effect" is something that savvy investors will have to be wise of with regard to making Standard legal card picks.