According to Bandai Namco's trends as I have noticed during the past 2-3 years, it's highly unlikely (I'm not saying that it's impossible) that they will release another Wii version next year. Releasing another one will be awesome with Taiko 12, 12 (Remake) and 13 songs; but it's highly unlikely.
Since Wii has got a lot of new and popular songs, I predict that they may release another DS version since the previous one had only 50ish songs. It'll be cool to play KitaSaitama on the DS, lol.

I guess my touch screen will break.
And who knows??? They might release one for PS3 as well with over 100 songs... (which means, I need to get a PS3...)
For references, these are tracks that are not released to domestic console versions that I know of...
DON'T CUT (Taiko 12)
Chikuzei ~Gear Up~ (Taiko 12)
Haikei, Gakkou Ni te... (Taiko 11)
PaPaPa Love (Taiko 11)
Rumble Ranbu (Taiko 12)
Taiko Ranbu Kaiden (Taiko 11)
Caramelldansen (Taiko 12)
Mikaduki (Taiko 10, 11, 12)
Alones (Bleach) (Taiko 10)
Takio's Shoran 1 and 2 (Taiko 9, 10)
Spurt! (Taiko 9)
Fundari Kettari (Taiko 11)
Melt (Taiko 12 - Remake)
Prisoner of Love (Taiko 12)
Magical Sound Shower (Taiko 9)
Symphonic Motos (Taiko 10)
and so many more...
I sound like a Taiko scholar... *blush*