How is sharing the lockout a good thing? I'm not really seeing how the number of available runs per week being halved is a benefit to players. As for catering to casuals, how? Take someone like myself. I have a grand total of two 80s. So I can run a total of four raids per week which will be cut down to two. That's better how exactly? I can understand the hardcore people seeing the benefit that they no longer "have" to run through the same content with each of their 10 80s, but I really don't see how this is catering to casuals at all.
Having the same loot is just retarded. Why bother trying to get 25 people together for a run when the same shit drops in 10man. You put up with the added frustration and possible drama of a 25man because of the better loot. Sure you'll get less drops in 10man, but also less competition, drama, annoyances, etc.
Maybe I'm just being oblivious and missing something, but it just doesn't feel like Blizzard really thought this one through all that much.