Pictured: custom armor value applied to armor (not working currently)
Jeb recently revealed that armor in 1.9 will not, for the time-being, have armor durability degeneration, something that conflicts with the armor having applicable custom attributes. In short, that means armor will have the option of custom attributes (armor values, special effects, etc), but will not degrade. Neat! While the degradation mechanic may return in the future, it is currently not compatible with custom attributes on armor, something Jeb felt was more important.
Regarding custom armor attributes: what sort of crazy attributes can you think of to stick on armor? Would you be fire-proof? Is it even possible to make armor "sharp"?