I do think that Kael needs some work in order to get people to use the zone. For me, I'm just not interested enough in the Barb illusion or Giant Slayer quest to go to Kael for anything other than a boss kill. If anything, I would remove the Kael armor drops and replace them with non-visible armor items. Give them stats on par with Kael armor and people would go there to help gear up. Right now there seems to be a bit of a gap in non-visible armor items from casual to raiding. Kael could be the gap filler.
These are already in Icewell -
All/All earring - Pure Ice
Caster ring - Pitted Iron Ring
All/All ring - Molten Ice
All/All neck - Necklace of the Frozen Snow
All/All face - Mithril Studded Mask
It would be nice to see in Kael -
Caster/Healer earring
Melee earring
Healer ring
Melee ring
Shoulders
Caster/Healer Belt
Cloak
Range
This would give people an option between Chardok and Kael for the other non-visible items you need before ToV.