The favor mats won't be completely worthless.
There's still the 170 accessories for both DoH and DoL that are crafted with them, and are quite viable alternatives to the new higher ilv ones.
Also.. glamours! The 170 gear makes for some nice glamours, and some people are too lazy to red scrip (now blue scrip) grind them and thus just buy from MB.
(170 dyeable, 180 isn't. I'm guessing the augmented 200 will look the same, but dyeable. Would be really cool if they had new looks though.)