Will you guys ever consider adding more CMs, perhaps old dungeons like Ragefire Chasm/Wailing Caverns?
Actually, the developers would like to add Challenge Modes to existing dungeons from previous expansions. No timelines or anything, though, but it's definitely something they're considering.
Challenge modes seems an excellent addition to the game, i myself haven't ventured off to try it, but we have had "similarities" in other dungeons, such as Heroics with Timers, which gave a reward if you completed within the time limit (CoT: Stratholme fexample, Achievment in The Deadmines heroic..)
This is something alot of people enjoy, and i love how you have restricted the iLVL, so it's not about who got the most time to farm raids, ofcourse i've heard having set bonuses that boost some of your classes abilities doesn't get nerfed when you enter, but overall, it's fair game for anyone who have had enough time to just simply gear up in 5man heroic gear, which makes this type of competetive gaming even available for the hardcore that doesn't have all that time anymore (Points at myself)
As for old dungeons i would love to see challenge modes in many old dungeons, the ones i would be most looking forward to would probably be Shadow Labyrinth in the Auchindoun in Terokkar forrest, i still remember the thrill of meeting Murmur for the first time, the excitement of that encounter & getting one step closer to Karazhan.
Edit: some typos