We've walked around aside the terminal and taken pictures of the ship and terminal; up in the terminal there is an outside deck right next to the ship that you can go out and take pictures and look at the ship (magnificant to see it towering above you); there is a coffee/snack shop there -- but things sell out quickly. If you want to get on and get ressies, I would definitely get in line early. We were so busy walking around and taking pictures that before we knew it the line was wrapped around several times inside the terminal and almost down the escalator. But it moves VERY quickly.
As soon as you cross the "plank", they take your welcome aboard picture. So be prepared to dump you stuff to the side quickly and pose!