People who think the Emerald Dream would be boring, or doens't have enough content, or is too shallow, or is just going to be fighting corrupted animals the entire time are very reminiscent of the people who did and still think that Mists is childish- close-minded, unobservant, and unimaginative people who won't or can't think about the larger story shapes and implications of a plot thread, or are afraid of a message of peace, tranquility, or preservation threatening their "coolness."
And why do people post the same stuff here and on the official forums? It's annoying that both forums are almost doubles these days.
People post it on Blizzard's forum because that's where feedback goes if you'd like to see it possibility implemented in some form.
People post it here because more people can respond and provide feedback as the forums here don't require an active WoW account or you to be in the same region as the poster.
As for the UI, I think it look's nice. Though not necessarily saying we need a new UI, but I would be surprised if they changed it to match the style of the Mount/Pet and LFD/LFR tool.