Zelda 2D was hinted by Emily a few days ago. Also, there are not many games besides those "Zelda 2D" which are often designated by their number of dimensions. It's Zelda 2D that he's talking about.
Both this and the heavily hinted MPT are probably gonna be revealed next week.
You're all gonna disappointed when Metroid Trilogy turns out to be a 3DS only game. Makes no sense but totally something Nintendo would do.