Last year I visited WDW and cruised. The selection of scrapbook materials is much better at Downtown Disney, which stands to reason since they have much more physical space than does the ship. Most of the stuff at both locations is WDW and character-oriented; very little is specific to the cruiseline.
If you like "value packs" of colored cut-outs and stickers with coordinating paper, you'll likely find something you'll enjoy. If you're looking for more creative things sold item by item, you'll be disappointed.
One warning: be careful of the scrapbooks themselves. I bought a 12x12 navy blue scrapbook with Tinkerbelle on the front. I assumed (always a mistake!) that I could add pages to the book to enlarge it. Instead, it has an odd kind of spine make-up; you can take it apart like a post-bound Pioneer scrapbook, but the spine doesn't "grow" if you add more pages, and your posts will be visible. Of course, if you only want 10 pages (perhaps for a character signature book), this isn't a problem!
