Today the option of using a Story-skip potion for both ARR and Heavensward has been confirmed in the latest letter from the producer Live.
Additional information and translations are still forthcoming, though from what I've gathered the mogstation potions will have three different types:
1) Rush you to the end of ARR -- 2.5 and allow you to enter Heavensward instantly.
2) Rush you to the end of ARR and Heavensward 3.5 to allow you to enter Stormblood instantly
3) Level a job of your choice (likely only combat) to 60. One time limit per account (restriction may lift after observing its use). RDM and Samurai won't be eligible as they start at level 50.
Availability: June 16th (Subject to official translation)
Price: $18 for ARR story completion; $25 for both ARR and Heavensward. Unsure on the level potion, though I'll update later tonight.
Additionally: A new video showcasing some new Job actions has been released: