Square Enix has http://www.square-enix.co.jp/tgs08/titles/ their list of titles they'll be dishing out at the Tokyo Game Show, indicating which are playable, and which will video-only at the October event.
Final Fantasy XIII, Final Fantasy Versus XIII, and Final Fantasy Agito XIII are showing up as video only.
Hopefully they'll be on the outside of the usual Closed Mega Theatre, and be more than just trailers.
At least a video walk-through of gameplay is something to hope for. More PlayStation 3 News...