I'll help you out here:
We're currently in the process of a major client update for MoP. Once this update is done, it will enable us to implement a ton of features that were previously impossible or extremely time-consuming for us to implement. In the light of that, the update will also resolve several annoying client bugs like the double loading screen issue.
As for Throne of Thunder heroic, I am happy with the state it is in. We are in the process of performing some tuning that will ensure it is a good (and challenging.) experience for you guys.
On the topic of old raids: Since we rescripted a ton of content for Lordareon, I am in the process of porting said content from Lordareon to MoP. In the near future we will open AQ20, AQ40, BWL and Ulduar on MoP for transmogrification farming purposes.
As I am mainly focused on PvE related development I won't make a statement about class fixes and whatnot, but the information Takenbacon previously posted in this thread holds true. Rest assured nobody has forgotten Frostwolf.