The two most photogenic areas that I am familiar with would be the Courtyard (fountain) at the bottom center of the map (open all 3 days) and the 4th Floor terrace which is now open on both Days 2&3.
The large parking lot outside the west halls is still being used, but now the area right outside the west halls is now open to cosplay as well. The same thing has been done at the east halls. Of note, there is now an outside walking path between the east and west halls as a result of opening up the outside areas around the halls.
There also seem to be some indoor cosplay areas. One at the end of the east halls on the second floor, one right at the main entrance when you enter (which seems odd), and it would appear that the entire middle area at the west halls is now a cosplay area.
The men's changing room is now up on the 6th Floor. There will be a long escalator ride up near the main entrance. The women's appears to be in the downstairs area near the main entrance.
If you stare at the new map at the bottom of the previous page long enough, it starts to make sense.
Here is the new updated Cosplayer Handbook
for the event.
Good luck, and good hunting.