Running Karazhan in T6 (equivalent) isn't any more fun than running it in instance blues. It is still the same raid we've done for the past year.
But we have ZA! Yes, we do, and casuals don't seem to want to do it. Why would they? They can get better gear from farming Kara for badges and with few to no wipes. I want to do ZA, but there aren't many people to do it with. Somehow I doubt Sunwell will be any different. Why do challenging content when easier stuff gives the same or better rewards? This isn't an attack on casuals, they're doing what they've been taught to do: follow the gear along the easiest path. ZA could have been this path if not for badges.
What are we going to do with the badge gear anyway? It's not going to suddenly make ZA easy enough to be farmed constantly.
Blizzard, give us new content, not distracting gear that is nothing but bigger numbers in the same old instance. Give raiders more content too. It doesn't need to be the next tier of gear, frankly the tiers have come out way too quickly, we should not be at T6 so soon. Add more raids. Maybe they'll only drop sidegrades, so what? Make them fun and people will go.