From IGN:

Nintendo GameCube
Sept. 25: Baten Kaitos Origins
Oct. 9: Super Paper Mario

Nintendo DS
June 5: Big Brain Academy
June 5: Magnetica
June 11: Nintendo DS Lite
June 26: Sudoku Gridmaster
Aug. 28: Star Fox DS
Sept. 18: Pokemon Mystery Dungeon: Blue Rescue Team
Sept. 25: Mario vs. Donkey Kong 2: March of the Minis
Oct. 9: Clubhouse Games
Oct. 30: Pokemon Ranger
Oct. 30: Children of Mana

Game Boy Advance
Sept. 18: Pokemon Mystery Dungeon: Red Rescue Team

No mention of the new Donkey Konga game or Twilight Princess GCN release dates (understandable for the latter obviously).  That DS list is missing, amongst other things, Yoshi's Island 2, Phantom Hourglass, and Chibi-Robo (I assume Chibi-Robo is getting a US release; E3 showings are no guarantee).  I guess all 5 of those are going to be in November or December.  I predict Twilight Princess (along with the Wii) will release no sooner than November 6th-7th and the other titles will be sprinkled throughout the rest of the year.

And still no mention of Mother 3.  I guess they didn't want to make that crazy GBA release list even more bloated... I'm not so sure Nintendo would drop that in the midst of the Wii launch and the holiday rush.  I'm also curious why, what with all the DS games listed and the rest shown at E3, the month of July is void of any release at all---July would be a perfect month to release both Mother games on the GBA in the US...

For the missing DS games, I agree with Nov. - Dec. timeframes with the exception of Chibi Robo which I wouldn't expect until 2007.  As for Twilight Princess, IGN seems to think the Wii might actually launch in October.  I think an 11/19 launch is more likely, even if it puts the system two days after the PS3.

As for the month of July, remember that this is usually the second slowest month of the year (April is the slowest).

Other games not mentioned were FF5 and FF6 for GBA which Nintendo is publishing.  I assume we'll see these in either Nov. or Dec.

System launches the week of Thanksgiving, even the week before, are such a bad idea.  They should reach the hardcore early adopters first no less than a month earlier since they are the ones that will buy more software sooner.  The word-of-mouth could be good for not only hardware but also software sales for both the hardcore and those Christmas shopping, especially if the launch line-up is almost 20 titles.  I don't see how kiosks are possible with this system so Nintendo may very well depend greatly on word-of-mouth.

An October release does seem possible since there is such a gap between 10/9 and 10/30.

As for July being a slow month, is it slow for any particular reason?  I could at least see portable game sales go up during that month due to vacationing.  I can see why sales are down---no one releases anything, but that's fine for those of us with shelved games that either need to be finished or haven't yet been started.  For instance, I had never finished the GCN launch title Wave Race: Blue Storm and currently working on the Expert Championship... no matter how many Wavebirds I go through to make it happen.

I think it's just the traditional mentality of the U.S. entertainment industry surrounding perceived summer behavior.  Marketers don't want to risk pushing a product to consumers who aren't going to be around to hear about it.

I really don't see why they don't evolve past this delusion.  With the internet and cell phones, there's no reason why marketers shouldn't be able to reach their target consumers anytime of year, and the benefit of releasing titles into a deserted marketplace is just waiting to be capitalized on.  Over the course of many summers, I've continually seen bored gamers heading to stores looking for something new to play only to leave empty handed.

I can't believe that the major game companies aren't aware of this phenomenon, so I can only assume that there's some cost/benefit analysis going on that determines that the risk of a title not taking off immediately isn't worth the potential forgone sales.  I think this is short-sighted, but I can sort of understand since most games have tragically short lifespans (if they don't sell at release they're usually done for).