I think the new major number Firmware will have:

The ability to transfer a copy of the firmware locally for people without access to Wi-Fi without.

The ability to get SpotPass updates for the pre-install App "AR games", so we can get those tons & tons of new 3D Augmented Reality games that Iwata mention in 2010 and/or 2011.

The ability to record in 60 fps per camera with the 2 outer cameras at once (3D standard since 1930's) and have option for 24 fps & 30 fps & 48 fps & 60 fps for recording, and to always have photo mode at 60 fps instead of 24 fps. (the video recording currently does 30 fps per camera at once, since first release)

12 more slots for StreetPass. (total of 24) (well I would want)

To have HTML5 in multitasking Web Browser (well I would want)

More features in multitasking camera

Brightness to stay just as high in 4 & 5 when unplug from charger

The ability to add photos & screenshots to background.

Get rid of ghost effect in OS when black background is around, while also having more depth in OS.

New StreetPass Find Mii game that lets you use up to 300 Mii's at once as mention by Iwata during 2011.

SpotPass Mii's to work like StreetPass Mii's instead of just name & date of receive in plaza. (well I would want)

The ability to zoom in on Puzzle Swap images with the R button and zoom out with the L button, and press both L+R at once to reset distance in view.

Okay so 3 of them are not predictions but wants.

Well if I can think of anything else I personally want then I will add to OP.