Yeah a few months ago at the Anime Expo they had a panel for the film with Avi Arad in attendance. He confirmed that they want to use some of the score and since Kenji Kawai visited the set and had a positive experience it was 99.99% chance of happening.
Other bits from that panel:
- Production I.G was heavily involved in the pre-production.
- Daisuke Aramaki will only speak in Japanese in the film
- The city the live action film takes place is left "ambiguous" but the city feels more like it was depicted in GITS than a generic "Sci Fi future city".
[*]Tachicomas may appear..
- Filmed mostly in New Zealand because WETA is handling the visual FX, props and sets and so everything was available to the production there. A lo of the film is practical FX vs CGI.