They're more likely (not swimming pools, but other things) on the A380. There's 50% more space than the 747, but payload is 35% more, so it can only take 35% more passengers. Most of the airline layouts published so far have had fewer additional passengers as compared to the 747 than that (typically around 500, rather than the expected 555), so there is more room to play with. Expect it to be used for first class and business before you see much benefit in cattletruck though. The plans published so far have been 2-4-2 on the top deck and 3-4-3 on the lower deck for economy. 3-4-3 is the same as a 747, but the cabin is 19" wider, so each passenger gets about an inch more width and wider aisles.