We're completely aware of how quickly players consume content. We're also aware that not all players have consumed all of the current content either. Does that make us less aware that there are many who are ready for more? No. But, we want to make sure we deliver our best with Mists of Pandaria and it won't be long until you start seeing a lot more of what we have in store for it and for you.
With all the brew ha-ha about the change in the talent system and overhauls in how some classes work in general. What are the odds of there being a free trial version of MoP to see how we like it before we commit to it and spend the money on something that we won't be able to even sell to a used game store?
As for people that haven't seen current content... I don't really see how you guys could have made it ANY easier. If they haven't seen it now, then I can only assume their seeing eye dog doesn't know how to play.