I have been working under the assumption that it would behind TSMM, but when listening to the most recent Jim Hill podcast (yeah, I know people's feelings about Jim), he said it will be going in the LMA area. I am not taking his word as truth but it did get me thinking about this option that I hadn't considered before.
Things that make me thing this might be, 11 acres fits nicely in that area and the concept art seems to show the land having a roughly tri-angular shape towards the back which fits with the current shape of the back of the park.
Against this option, the TSMM building in the artwork does look like the side of the building and not the end, and this would put the main entrance backstage, although that would make some sense if additional Pixar areas where eventually coming.
I am still leaning towards it going behind TSMM, but I am not ruling out this option.
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