Ok ok, fourth wall broken, we’re actually just temporarily removing them from the game for 5.2 due to the new raid tier. The idea with the item upgrade system is that it’s a way to spend currency on upgrading items when buying new items isn’t the clear path. Either you’ve bought everything, or at least most of them, and then spend currency to get that extra *oomph*. With a new raid tier coming, we don’t want to create a trap where people are wondering what’s more lucrative: spend currency on new items, or on the new gear appearing on vendors? (Hint: It’s the new gear on vendors.) To help ensure we’re not indirectly encouraging anyone to spend their currency somewhere they probably shouldn’t, the item upgraders will be taking a break.
Right now we’re planning for them to return in 5.3, which will not have a raid tier, and offer upgrades again as people will have likely have some currency to burn. We’re not sure yet if we’ll continue this cycle of having them take a break for raid patches and then come back in non-raid patches, but we’ll continue evaluating as we go, absorb feedback, and let you know how these plans evolve.