I specifically added the part "before any further bonuses" because there are plenty on both sides. For example stuff that improves Obliterate or Howling Blast/Rime:
- Freezing Fog (talent)
- Murderous Efficiency (talent)
- Icecap (talent)
- Obliteration (talent)
- Nothing but the Boots (artifact trait)
- Blast Radius (artifact trait)
- Ambidexterity (artifact trait; might've been already included in Maxweii's numbers, I don't know what traits he has unlocked)
- Over-Powered (artifact trait)
- both T19 set bonuses
- Koltira's Newfound Will (legendary item)
I can totally see that depending on what talents you choose (or put another way: what combination provides the highest DPS) and what gear you have, Remorseless Winter might be included in the ST rotation. But TBH I'm rather skeptical that it actually will be despite its damage being so close to Obliterate. My guess is that all the small bonuses to Obliterate and Howling Blast you get from your artifact combined with probably taking at least one talent that improves either, Obliterate will come out on top for ST despite costing two runes. But I agree, we'll know more once we have sims. I mostly wanted to add that there is much more to Obliterate than just its pure damage. Rime being the most obvious effect.
As a sidenote: I find the comparison to DnD/Defile rather weak. If I'm not mistaken, you don't use DnD against a single target on Live. Also, unholy runes are pretty weak for dual-wielding frost DKs anyway so anything that uses them and provides decent damage for that GCD is welcome (i.e., Defile).