I think Nintendo will have a N-Direct a week or so before TGS, announcing pricing and revealing some more attractive/ high profile Japanese software, that way they can ride the good-will (hopefully) of reasonable pricing and their announcements through TGS, where the Japanese public will have the opportunity to interact with the system and Demo the announce games, albeit set up by 3rd parties since Ninty doesn't really have a physical presence at the show these day.
Until we're into october, with the console launching in November i'm not buying that there isn't a sizable amount of Japanese stuff being held back fora prelaunch blitz. I think out west we know most of the stuff other than the stuff we do know about but hasn't really been showcased (COD etc...)
Iwata, if i'm not completely remembering incorrectly simply said that information of Japanese Launch/Software wouldn't be reveals via a conference, but some other way instead.
Knowing that Nintendo has dropped Megatons and tons of quality software via ND for the 3DS multiple times, even announcing new Hardware (3DSLL), should it really suprise anyone that they are comfortable dissemenating information in that manner, even information as large as some more upcoming Japanese software and the Launch Price and Date of their next home console?
Confirmation of DQX at TGS is promising, the game is tailor made for touchscreen play in relatively minute Japanese houses, where if the house has just 1 or 2 televisions the time investment of an MMO may make offscreen play a very attractive option, also I wouldn't put it past SE to announce release the Fabula Nova Chrystalis games prior to Lightnings Return setting the stage for the game to make its way to Wii-U, they've hinted at a willingness to put mainline final fantasy on the system, and lets be honest I very seriously doubt that SE won't throw Nintendo at least a port when they bother porting it to the 360, and given how much business they do together. Capcom is bound to have something, perhaps an announcement of the next iteration of Console monster hunter for the system, and the announcment of the gold edition of RE6 coming down the line at the very least.
I think we'll have a much clearer picture of the Japanese state of the Wii-U by the end of the month, perhaps by the end of TGS, and I think people that have been assuming that there is none, just because Nintendo has followed its MO by not releasing a ton of details until late will be made to look hasty.
If the price is attractive Wii-U should dominate Japan, Vita games will start being moved to Wii-U and dropped on the Vita, per industry rumblings, and the PS3 is a dying system over there too. The systems' philosophy, while perhaps seen as cool and innovative by some american consumers is really made for Japan. Where here it is convenient and comfortable to be able to play console quality games around the house, in Japan it solves a many problems plaguing gaming in 1 or 2 television houses and apartments, and appeals to the Japanese preferences regarding handheld games, which have been much, much more prominent than consoles for some time over there. E3 isn't the place where Japanese games are announced any more, there were hardly and 3rd party Japanese games present at the show, period. Nintendo hasn't really released any information about the J-Lineup whatsoever, makes no sense to Assume nintendo, who has been making big inroads with 3rd parties in Japan, evidenced by the 3DS, would make such a collosal mistake of having pretty much nothing for Japan, even if they don't make it out for launch there will be goodies announced. Now, if October roles around and still no peep, I'll start to worry, until then I think everyone can agree that until Japanese Launch details are announced in any form and TGS passes that anything could happen giving Nintendo's announcement preference.
Personally, i'm not really worried about Japan, the Wii-U is largely and unknown there right now, there isn't so much of a bad taste in their mouths on account of E3. I can buy Japanese Publishers hedging their bets on the PS3 in light of the performance of the PS2, but the Wii-U is coming off of too big a phenomenon for the same excuse to work. Sure every once and a while someone like Kojima will ignore it in favor of technical wankery, but to mid and small sized Japanese studios the Wii-U may literally be a lifeline, and Nintendo can form partnerships, as is their habit as of late to get some more exclusive, but still high quality software.
I'm not going to pretend Western Publishers will do anything more than give a decent amount of ports, provided the Wii-U is a sales hit, and likely less, except in certain cases such as games suited to the Pad, and Developers like Ubisoft, whom nintendo is very cozy with.
But I think they'll have a very diverse, and unique Japanese lineup, with a good amount of exclusive game from mid- mid high tier developers such as Atlas, Platinum games, Mistwalker and their ilk, along with enough of the big Capcom, SE, and eh, maybe not Konami to be the Japanese gaming enthusiasts go to console.