I think this will be the best Mario game since Mario 64. There's nothing bad about Sunshine or New Super Mario Bros, but they were not designed in a way that people were making them up to be. First 3D Mario game in 5 years, and first 2D game in forever - but both were not designed like a games that were years in the making. Sunshine was designed more as a sequel summer diversion type of game that would have been better suited to have been released on the N64 in the summer of 99 or 2000 rather than something that bridges generation gaps. It should have been the Majora's Mask of the N64 type of game rather than the first Mario game in 5 years on a powerful console.
New Super Mario Bros also was designed in a similar way - it seemed more of a game design to follow the old Game Boy lineage of Mario games of Super Mario Land, than a game that should be considered the followup to Super Mario World or something.
I think its important to point out that these games are very similar in design in that the "worlds" of each level did not differ crazy amounts like Mario 64 or Mario 3, and the powerups of both combined were more barebones functional powerups rather than an intricate part of the design. Waterpack, or the minor powerups in NSMB didn't affect the game like Racoon Mario or Cape + Yoshi Mario combo.
This game looks like it has decent changing powerups for each level, like SMB 3, the varying level design of Mario 64, and the waggle controls and galaxy mechanic looks something like the high flying element of Super Mario World. This to me is why it looks completely different than the games Sunshine and New Mario were, or were trying to be.