Here is a run-down game-by-game. Mostly, the games that have not (or will not) make it to North America are often Japan-centric or examples of game types that don't sell in the US. A game-by-game information follows.

Mike from Morgantown

2007
EyeShield 21
Reason: Japanese Magna series.

2008
Wii Chess
Reason: It’s chess. Third-party substitutes (Fritz Chess) exist.
Disaster: Day of Crisis
Reason: Apparent NOA decision. Did not fit with system theme (M-rated). Mediocre critical reception.
Everyone's Common Knowledge Television [Never released in the USA]
Reason: Japan-centric current events game.
Fatal Frame 4
Reason: Apparent NCL decision. Mediocre critical reception. Buggy game. Rights issues.
Captain Rainbow
Reason: Japan-centric game that would not translate well

2009
NPC Pikmin 2
Reason: NPC games did not sell well in US. (NPC Pikmin can be commonly found for USD$20 or less)
NPC Chibi Robo!
Reason: NPC games did not sell well in US on the Wii.
Another Code R
Reason: Point-and-click games have not sold well in US. Part of non-selling first-party lineup in 2009 in Japan.
Tact of Magic
Reason: Game did not sell well in Japan (10,000). Part of non-selling first-party lineup in 2009 in Japan.
PokePark Wii: Pikachu's Great Adventure
Reason: Name a Pokemon game not to make it to US since the original Stadium. Wikipedia lists a Spring 2010 date.
Everyone's the Star on the NHK Red-and-White Quiz Battle
Reason: Japan-centric quiz game.

2010
Xenoblade
Note: This is Monado: http://news.vgchartz.com/news.php?id=6789)
The Last Story
Note: Announcements expected in March: http://news.vgchartz.com/news.php?id=6788
The Legend of Zelda
Note: See E3 2009.
Kirby Wii
Note: Name a Kirby game that has not made it to US. I can’t find one since the Nintendo Satellaview SFC add-on.
Kensax
Note: Party game collection that may not make it out of Japan.
Start with 100 conversations NHK
Note: Sounds like a Japan-centric title.
Zangeki no Reginleiv
Note: No news yet. May or may not make it to US. May depend on reception of Sin & Punishment 2.

Wii Chess wasn't a retail release in Japan iirc, it was WiiWare only.

We're obviously going to get Last Story, Zelda and PokePark, those aren't even debatable imo. I think Reginliev is more likely than not too, if only because NOA desperately needs/wants both Motion+ content and "mature" hardcore content. Another Code R, Takt of Magic and the remaining NPC titles are longer shots, but I could see them making it as well honestly. The rest have no chance, unless by some miracle Tecmo Koei grows some balls and localizes Fatal Frame themselves.

NPC was discontinued in NA, so no more titles will be making it over.

Only NPC Pikmin and DKJB were.  NPC MPT is still in production.

I still think we might get Pikmin 2 given it's already sitting there waiting in english.  Chiborobo is less likely, since they'd need to dip back into the GC version to relocalize.

"Japan has got 17 more 1st party titles, which makes me ask why, if it's their weakest region."

It's not. Remember the yen exchange rate in foreign countries hurt their profits. So Japan is actually a lot stronger right now. In fact, that's probably been strong even with better exchange rates before.

E3 could possibly change everything.

Hopefully E3 will bring some good news, I jumped to conclusions. I admit it because I am drunk right now ;O.

But yeah, many will be making it here, but may not be doing it in 2010 though.........

I think EU has more localization problems...in the official Line Up there are only 5 Wii games!! I know, in EU we have multi 5, so it takes longer...still, this is a good reason to become bigger, especially in the localization department, while they can incorporate some new teams for Nintendo Japan...

I was pretty much trying to point this out a while ago. The Wii was getting really bad support from Japanese developers in the beginning. Not so much from a lack of games being made (as Japanese developers were pretty much the only ones making games from it) but as in those developers never bringing the games to the west.

Over time, this turned into the problem we have today, of poor support for the Wii overall. As the market in Japan for consoles deteriorated and focused on the DS/PSP, Japanese developers focused on trying to put their major console ideas on the HD consoles, while skipping over the Wii. While in the west, most companies were already skipping over the Wii from the start or only using it to make quick cash with 'causal' titles like My Sims Agents or Blom Blox.

A lot of the reasons you can trace the 'failure' of the Wii is simply because the Japanese companies either never tried to bring their good games over to the west or never marketed the ones they did bring over.  By the time Japanese companies actually started bringing over their good games, the only stuff we were getting was stuff like Muramasa, Little Kings Story and sequels to rail shooters like Resident Evil.