Just some thoughts from my brain. Both Disneyland and DHS are said to be 14 acres so would this put Stars Tours in Orlando outside this new land? I mean from what I hear, Star Tours out West is in Tommorow Land.
I assume both lands will be the same as a way to cut down on R&D (or however imagineering splits out design cost) and since they are both 14 acres, it seem to make sense.
I would think that Disneyland will start construction before Orlando. This is just me being (somewhat) cynical, but I can't help but believe there is a strong business case here for the folks out West to bear the larger share of design cost here.
Here is my thinking...I do not know the details, but I did hear that California extended a tax breat to Disney if they spend a certain amount out there over the next 10 years or something, I really do not know the details and I have heard that they bought more land out West, so I am certain that they will have no trouble meeting their commitment (it may even be a 30 year deal)...so my thought process (again, I really do not know the details of the tax break) is that Disney, as a company, would look to save from said tax breaks by having the West Coast park bear the lions share of the design for this new land and as such, they would want to be certain to get started out West first.
Again, I am being a bit cynical, but it makes sense for business to take advantage of whatever breaks they can get.