Here's some information from the current issue from Famitsu magazine that's only for the Japanese gamer audience. Seen from the E3 trailer, the silver-haired trio stands before a group of people in the city of the Ancients. Kadaj giving a speech tellsforth of a mysterious power that will wreak havoc upon the city. Not known if it was to be Sephiroth shows concern. On a more character note, Tifa and Cloud are somewhat distant from each other after the events of the game. Tifa and Cloud do not speak of one's name as well as they do not live together. The death of Aeris is still in both their minds and that's a barrier for both of them not to be together. ( Awww boooooo! )
Tifa fights in the movie for a reason, which yet unknown. She gets herself pulled into the madness fighting off Midgar and at the same time still manages to serve the people of Sector 7 at the Seventh Heaven Bar. The Turks play a minor role in the movie as they are wandering mercenaries ever since their former boss Rufus, who was the owner of ShinRa enterprises died from Diamond's attacks in VII. Most of the employees at ShinRa died, including Elena, Tseng and Reeve who were also announced deceased. Reno and Rude are the remaining Turks alive carrying out business for themselves and the silver-haired trio. No word yet if Cait Sith is to be shown, but Nomura says he will bring back characters that fans wanted to see the most come back. (I doubt Cait Sith was ever one of them.)
Getting on to stage placement, the scenario for the movie is about 50% complete and the japanese voice actors are already been selected and hired. No word yet either on who will be the english voice actors for the U.S. version, but sources say voice-overs for the english version has already begun.