I really think that I'm looking forward to this feature for 2 reasons:
1. I hope that it gives me that 45-minute baron feeling I had back in Vanilla (while just wearing dungeon Tier 1.0 and working toward my 1.5 set)
2. I hope that it helps non-hardcore players become more hardcore.
Let me explain #2 a little more. I think that LFR was great in terms of giving players more accessibility to content, but I think it was a GIGANTIC step back in Blizzard's approach to "we make games which help casual players become hardcore players". LFR helps casual players see content and get free loot while never helping them be better. You find me a single casual wow player who became a better player "thanks to" LFR. The only way I could believe that to be true is if maybe he had never raided before, saw how cool raiding really was and then was motivated to get better on his own, got better, did better numbers, then joined a raiding guild. You can play an entire expansion in LFR as a casual player and never improve your dps. In fact, the quality of player doing LFR toward the end of an expansion is worse than the beginning. After 5.0.4, testing new keybindings and bars with class changes in LFR, I saw morons who had no idea how the mechanics worked and worse, trolls who purposefully told people to do the opposite of what the real mechanics were to try to wipe us. Overall LFR doesn't pressure any individual in the raid, it just doesn't. Individuals don't matter in LFR since all you need is 10 capable people and LFR is still completable.
The journey of mastery is a tough journey. Having the right, repeatable challenges available to test and hone your skills is key. No one gets better on training dummies alone. And that's where challenge modes can help with that. Challenge modes help small groups of people get better. If a bad player doesn't even get bronze, hopefully they will be motivated to at least get bronze. If an ok to good player gets bronze, maybe they will be motivated to get silver. If a great player gets silver, maybe this challenge will help them hone their skills to get gold. If the challenge is there, people hopefully if they wish to "master" their character, the content, and the game... hopefully they will be motivated to get better and this challenge mode system gives them that progressive path, progressive challenge to slowly over time become BETTER. Not just able to beat it eventually thanks to being more highly geared, but able to beat it because their skill has improved.
Let me give you an analogy. In Starcraft II, the achievements on the storyline mode made me a better player. The challenge of getting all those storymode achievements on all the difficulties really pushed me to become a better starcraft player. Now, am I a good player vs player SCII player, no... but I'm better at the game than I was when I started. I think challenge modes can do the same for WoW players who want to get better at the game. People rarely can improve just by reading stuff on a website and sitting on a dummy. They need a goal, they need that challenge which pushes them to become better. That's why heroic raiding makes good raiders into great raiders over time.
One final good / bad (depending on your perspective) this could help with player skill evaluation in fact... maybe your average player if they work hard can get a bronze, but maybe for a hardcore guild you require all your players get silver... almost as a skill check. Maybe for the super elite guilds, they require players get gold. This could pressure players who wouldn't otherwise "care" about challenge modes to have to do it. I dunno, just an idea. Could be good, could be bad, could be indifferent.
Livistos, Undead Priest, Guild Leader of HILYMI since 2006
ESAK - Explorer 80.00%, Socializer 66.66%, Achiever 33.33%, Killer 20.00%