The way i see it, Gear scales too fast too narrow and isnt all that hard to aquire. Even gem-platinum and dragonscale is a dime a dozen, but you cant just add on a higher tier armor because whats better than Ruby Platinum? 100% protection? One problem is, the protection just raises too fast. An alternative would be to reduce the protectioned off by many armors, and give them other benifits like obsidian/adamantium do. Emerald platinum armor could offer much less speed penalty, others could offer Resistances, or a bonus to weapon skills, maybe even SP regen on diamond platinum?
The goal would be to make all of the gem armors more of a "mid" tier than end game, reducing some of their protection values leaves room to then add higher tier armors that are harder to aquire (need a reason to fight newer/tougher mobs!)
and maybe require a lot more parts to make. Even Enchanting is starting to feel a little easy and definitely more potent than smithing.
Obviously would need to see new Leather/Cloth armors for rogues and wizards and bone/fur for barbs that dont add a lot more protection. Like weapons, its all about slight upgrades.
Also for barbs, wouldnt really need to design new armor models, give us scale that looks like plate ;) has the same aesthetic affect.