The next update to Guild Wars 2 will feature some big changes to attribute-selectable gear. The goal is to "reduce the confusion about which attribute combinations are available on any given piece of gear". Moving forward, most attribute-selectable gear will only feature attribute combinations available on a player's account dependent on the expansions owned. Exceptions to this reset include Crafted Backpacks, Elite Specialization Armor/Rewards, & Attribute combos related to raids & fractals.
When the next update goes live, players will find gear attributes reset and will need to reapply combinations in inventory and on equipped gear.
Crafted gear will also be tweaked for "consistency". Selections from several gear sets are being adjusted to make "it more obvious which attributes will be available in each prefix family.
Attributes on gear with the Assaulter’s prefix will now have either power or ferocity as a main attribute (although no attribute combination with ferocity as the primary attribute currently exists), or it will have two secondary attributes that support a power DPS playstyle. The Defender’s gear attribute selection likewise will have either toughness or vitality as a primary attribute, or both as secondary attributes. Healer’s gear will contain a choice with either healing power or concentration as a primary attribute, or both as secondary attributes. Malicious gear will have the requirement of condition damage or expertise as a main attribute, or both as secondary attributes. Celestial gear is being added to the Assaulter’s attribute selection, so it’s available on all four prefixes.
Check out the full post on the Guild Wars 2 site.