Yoshi said they were working on this on a forum post, that they were evaluating options based on which ones were least expensive in dev time versus client load. Having 10+ textures for every item would be a lot of local texture ram. Also they'd need a way to distinguish between the current versions, like the red Leather Crackows, which are for war classes, and the blue ones for magic, and the green ones for gathering and crafting. so they'd need different visuals for each of those level 25 boots, plus 10 texture colors each. Or even just 3 colors for each of the three new shapes. In other words, its another overhaul no matter which solution they pick, so it'll be awhile to do it right.

There's some other solutions too, like making only a few peices of gear for each slot per level range, but make each one simultaneously be good for, say, casters, crafters and gatherers (+MP, +magic potency, +Gathering, +Control on one pair of 25 boots). This would greatly reduce the number of item models, and make multiple textures more feasible. However, it would greatly change the gearing strategy of the game, and require ANOTHER balance pass to make it work correctly. Another expensive option.

Overall, yes, it needs to be done, but they've also got a full game revamp coming in a year, so spending the resources needed for the full blown solutions may not be in the cards. We'll see though!