I've been reading a lot of the recent QQ about people quitting the game for lack of content or "things to do". Be the drop in activity for real or just a mass perception doesn't really matter but there definately seems to be an issue at hand about how the raid-content is scaled.
In WotLK Blizzard successfully introduced a lot of players into raiding. They did this by making epics accessible and content easy. In this regard, WotLK was a very successful expansion and a large portion of gamers have since become accustomed to the idea that raid-content is part of their endgame.
With Cataclysm Blizzard has now removed this "raid-content" from a lot of players endgame because epics have become harder to get and even the first few fights require a certain amount of dedication on coordination (good leadership). For a lot of guilds and PuGs, this is too much to ask at this stage in the game. And these types of players that struggle with such content make up a large amount of the player base.
While in personally agree with Blizzards sentiment about making epics "epic" again and making raids at least somewhat challenging, they are cutting out a lot of their players with this attitude.
People have come to expect at least some easy and accessible raid content for them to pursue. And too be honest, even as a regular raider myself, I'm inclined to agree.
Tier 11 content has 3 instances. Blackwings Decent, Throne of Winds and Bastion of Twilight.
While the individual encounters are of varying difficulty overall the instances are comparable (except maybe Throne of Winds). What I'm saying is, that there is no big variancy in difficulty between the 3 instances.
If we categorise our raiders into 3 general categories: Casuals/Puggers, Dedicated (progress/completed normal modes) and Hardcore (progressing through hardmodes) the 3 instances Blizzard delivered only really cater to the Dedicated and Hardcore. There is nothing there for the Casuals. T11 gave us 12 normal raid-encounters and all are directed at the vary same audience.
If however, there was a clear difficulty curve between the 3 instances, I believe Blizzard could satisy a much larger portion of their player base.
Example:
-BWD becomes an "entry-style" instance. Not as faceroll as Naxxramas but with more forgiving mechanics than currently. Maybe the level of TotC 10 man normal.
-BoT becomes the "advanced" instance maintaining roughly the level of difficulty it has now.
-ToW steps it up a little again, preparing people for future hard-mode content.
Hardmodes could then be concistantely challenging in each instance, as there is no need to cater to Casual players at this level.
I realize this point will become moot once 4.2 is released and T11 content receives further nerfs. I do however think Blizzard could have done a better job in catering to ALL their audiences.