Maybe they should change Tempests Spine a little if they do decide to unlock an 'epic' option for that raid.
What do I mean? Well, I guess for starters, they could add an objective where you have to kill some enemies on the ground floor so that the barriers to the entrances to Tempests Spine will drop. They could also have the rune in Tempests Spine change around to either CHR, WIS, or INT on each trip inside. They could also add another boss to Tempests Spine after you kill fire and ice, a balance elemental appears by the chests and attempts to revive both of them in a ritual that takes 30 seconds, and if it is completed, both are revived, and he disappears. As the balance elemental is composed equally of all known elements, including force, it will be very difficult to take him down by arcane power. The underwater part could also have a optional leviathan boss that, while initially unattackable, can be attacked if it surfaces. The inevitable boss could have a 'fake' inevitable that we currently fight, and then buried into the wall is the 'real' inevitable that is the size of Sorgek and bursts out of the wall when the fake inevitable is killed.
Speaking of the end of the battle, that can also be changed somewhat. From the beginning, the portal is 1 way, meaning you cant go back in once you go through, and the only thing that surrounds the place are narrow columns, making it MUCH harder to avoid being knocked off the top, although you at least have a small glimmer of hope. The puzzle tiles also have a chance of changing randomly when Sorgek does his blowback attack, and he has more attacks, such as a attack where he leaps into the air and meteor swarms the place, a attack where he leaps into the air and comes down stabbing his sword into the ground, doing a blowback attack and causing large force damage. Other attacks include a flame breath attack where he does a 360 flame attack that does 30 seconds of 1d20 fire damage if a fortitude save is not made on top of the usual damage, a dash attack where he dashes foreward with his sword, inflicting damage and pushing everything aside in its path, and a final despiration attack where he leaps into the sky and calls down massive bolts of lighting down onto the platform whilst at the same time causing meteor swarms, ice storms, fire storms, acid rain, horrible wilting, and wails of the banshee. Yeah, its a despirate final attack, but if the party can get rid of the last 10% of his health fast enough, he wont have enough time to use it.
Overall, Tempests Spine was a great raid for its level, and to see it revived for epic mode would be great, if they do it right.