They have Hats, mugs and t-shirts. They hall have Japanese characters in front (I believe that it says, "Pacific Overtures, although don't quote me on that. On the back, it says, "Pacific Overtures in English."
When I saw the show last week, they were out of the XL t-shirts and didn't think they were getting any more in.
I was there in previews, but they were only selling t-shirts and the libretto. I got a t-shirt: it has Japanese characters on the front and Pacific Overtures on the back. There must be more items available for purchase by now.