All I can really say is that the longer they wait, the more likely we will have information leaked in some manner. They will probably announce the remaining characters before or around that time.
The last few weeks are generally a very big time for information slipping out anyway, because of stores managing the games wrong, smaller developers wanting a few seconds of fame, and all that stuff. So yeah. The last few weeks will probably have nothing shockingly new. Unless they plan to show off anything else online, I guess.
I'm thinking if they didn't show at TGS, then they wouldn't show up here. I'm really starting to think this is the final roster, and while I don't mind THAT much (still want Cloud in...), they should at least tell us.