Usually X.1 patches are extensions to the main expansions that precedes them. In 4.1 we will get things which didn't make it in time for 4.0 like the housing area. What really concerns me is that 4.1 follows the same formula as previous X.1 patches adding stuff we already expected. When Yoshi said he will reduce the number of dungeons from 2 to 1 every odd numbered patch it was because they wanted to add another type of content we never had before. 4.1 doesn't add anything "new" except the usual expected stuff. I guess Eureka should be this type of content but it didn't make it in time.