It's not the full song list, but there are a few new things to be seen in here. From a Korean Taiko fansite. Thanks to arien666 @ osu! for the find!
J-Pop and anime list. Two old songs in J-Pop coming, the Taiko classic Natsu Matsuri and Joyful (if you have Taiko DS3 you should have played this before), but there are two new songs in Anime, Lovers, another Naruto song, and Lion, from Macross F.
...Though, Natsu Matsuri has already been in Portable 1....why include it again? Are there any secrets this time?
Variety, Classic and Game Music genre, in that order. The only one with new songs here is in Game Music. Mappy Medley gets another run after appearing in Taiko Wii 1 and Bambini from Mojipittan (the Japanese word puzzle game) gets a second console outing after DS2. KARMA (Tatsujin Mix) is predictably here, it's a new Taiko 14 song. Magical Sound Shower, MachineGun Kiss and Hatsune Miku no Gekishou, the three Sega songs announced today on the Taiko blog, are here.
And a completely new one we've never seen before. '無慈悲な王' or 'Heartless King' is the second song from God Eater after No Way Back (link to the song). Look at the kanji! Anyone want to bet this will be a 10* on Oni?
Namco Originals. Much as we would like to see stuff leaked from this genre, there is nothing new to show from this list...too bad. Pastel Dream is here, however, the Angel Dream 3 we've been talking about for a few months now.
Note that none of these songs will be placed in the list on this site until official confirmation is received, but they're probably not fake anyway.