Castlevania: Mirror of Fate
Project X-Zone
Pokémon X/Y
Pokémon Mystery Dungeon. Gates to Infinity?

Maybe:
Luigi's Mansion
Monster Hunter
Some unannounced game, like Layton vs Wright.

Exactly the same, and I'm too lazy to write it, so I quoted.

I'm probably getting 5 day 1:

Fire Emblem: Awakening

Etrian Odyssey IV: Legends of the Titan

Shin Megami Tensei: Devil Summoner: Soul Hackers

Project X Zone

Pokemon X (probably)

Unless I'm forgetting some or there are more unannounced ones yet to come out in 2013 that I will want (Shin Megami Tensei IV localization and Advance Wars 5/3DS, please!), this should be the extent of my 3DS day 1 purchases.

Pokemon X/Y
Luigi's Mansion
Fire Emblem
Monster Hunter 3
Project X Zone
Animal Crossing

Maybe: Castlevania, Shin Megami Tensei, Etrian Odyssey IV, Mystery Dungeon

Overseas: I would buy SMT4, MH4, Bravely Default, DQ7, Youkai Watch, Rune Factory 4 if they come over this year (I doubt it for most of them, especially Youkai Watch)

Castlevania: Lords of Shadow - Mirror of Fate
Monster Hunter 3 Ultimate
Luigi's Mansion: Dark Moon
Fire Emblem Awakening
Project X Zone
Mega Man 2-6
Shantae 3
Professor Layton vs Ace Attorney
Phoenix Wright 5

i may be a little too optimistic about the last two though

Luigi's Mansion: Dark Moon. That's it for the whole year.

Fire Emblem and MH3U for me. I really doubt MH4 will release in NA this year, otherwise it'd be 3.

Animal Crossing New Leaf will be the ultimatum of first day purchases for me.
Pokemon X and Y might be a first day purchase, but this depends on how much money I'll have at that time.

I'm getting quite a few of 3DS titles day 1 here's my list.

1. Fire Emblem Awakening ( I already got this pre-ordered through Gamestop. I hate them, but I want that artbook so I have no choice)
2. Luigi's Mansion Dark Moon ( I absolutely love the original game. Such a under-appreciated game)
3. Pokemon X
4. Pokemon Y ( I'm getting both versions of this game. One for me and the other for my Bro)
5. Animal Crossing New Leaf ( Can't wait)
6. Monster Hunter 3 ( Getting this along with the Wii U version)
7. Pokemon Mystery Dungeon 3DS ( March is going to hurt my wallet so much. Lol.)
8. Project X Zone ( Gotta support these games so more can come over)

The games that are a maybe are:

1. Castlevania  : Mirror of Fate ( I'm iffy on this one, I need to know more details)
2. Etrian Oddyssesy IV ( Haven't played any game in game in the series)

Pokemon X or Y
Dragon Quest 7