https://www.wowhead.com/wotlk/news/l...classic-328956
So, the way I'm understanding this:
Once Ulduar comes out, 25man loot (213) is going on the 10man loot table. the 10man loot (200) is going to a Heroic Plus mode that is harder.
I'd assume something similar to this will happen when TOC comes out (Uld10 going to H+ and Uld25 going to Uld10) and so on.