Just hoping for something thematic and viable for the new elemental focuses you have us Sorcerers using. Come endgame, Fire Savants get 2 robes, Air Savants get 1 incredibly useless robe, and Water and Earth Savants don't get anything.
DT is always nice to have, but I think something more specific to each element would be more cool/interesting.
I would suggest to have similar bonuses on these as the ERD Robe does, meaning
Air: Superior Lightning Lore, Superior Magnetism VIII, Superior Lightning Resistance, Lightning Strike Guard, plus a few epic slots and other bonuses
Earth: Superior Acid Lore, Superior Corrosion VIII, Superior Acid Resistance, Disintegration Guard, plus a few epic slots and other bonuses
Water: Superior Ice Lore, Superior Glaciation VIII, Superior Ice Resistance, Freezing Ice Guard, plus a few epic slots and other bonuses.
Other bonuses should be more unique to each of the robes, to avoid a cut/paste approach.
If they end up as powerful as the ERD Robe, a similar grind should be used to get it.
Of course, those potency abilities won't do much until there are higher level spells, but that is a different issue for a different post.