In other news:

The more I think about it, the more likely I find it we're going to end up getting a DoT in a future Xpac.

The devs can't add "Jolt III", because in order to make our Verspells more appealing they have to be stronger than Jolt II, which is only 20 potency behind VF/VS and 50 behind VT/VA. In order to raise the potency of Jolt any higher, every Verspell needs to be increased too.
To add more potency to the base rotation, either they need to add more procs, more finishers at the end of our combo, buff our cooldowns, or straight up give us something to swap Jolt with; they just blew their load with Scorch and cooldown buffing, and they removed Impactful, so returning a variant of it at this point would just be disappointing.
But a DoT -- say, a 2-sec cast with an innate AoE spread -- could easily inflict more total potency than almost any spell in our rotation (and should, so we have reason to maintain it) and be continuously tuned free of the other Verspells (since at the end of the day we won't ever be spamming it), and so long as its mana gain per-cast exceeds Jolt, it can easily slide in to replace it.

And to this day I will never understand someone complaining such wouldn't "fit" in the rotation. Not wanting to maintain a DoT, fine, maybe, but if the duration is long enough it's hardly different from the rest of our proc gameplay.