This is just me, but I highly doubt the "all new 3D Mario" is going to be remotely related to Galaxy or 3D Land. It'd be a complete waste to push for a sequel to either on a brand new system. Really exciting stuff, all the same.
That Yoshi game is suspiciously similar to Epic Yarn (understandably, duuuuuhhh), but if any other franchise would take the torch from Kirby, it would have to be Yoshi. Given the bizarre, colorful, arts-and-crafts style that are Yoshi platformers, a yarn-based game actually makes plenty of sense.