I hope by "Final" they just mean for right now!
It'd be really nice if they took a break, took all the feedback they received and implemented it in some even cooler levels.
Though I'm really digging the look of the Mystery levels, one of my favorite parts of the free DLC pack was all of the branching paths.
I wonder if the team that worked on NSMB2 DLC is moving on to NSMBU DLC? I understand that different teams worked on both games, but it wouldn't surprise me if they didn't assign their A-teams to the DLC.
If you add me on any platform, shoot me a PM and let me know!