Here is the map:
As you can see, Universal has used 64, 65, and 66 for the three main buildings. They have added letters to divide up the three areas.
Here is what we know/think we know. Feel free to fill in the blanks on Twitter, Orlando United, or in our comments.
64E Platfrom 9 3/4
64G Kings Cross
65 Probably Ollivanders (permit talks about stairs for actors)
As always, follow us on Twitter for updates @Parkscope and @CaptMichael87