Yep. They already have most of the keyscenes where all people reveal to Kyon what Haruhi is and who they are and why they are there. That includes animation AND dubbing.
Also, the scene after "the dream" (where Itsuko and Kyon-chan are playing Go in the club and discussing how that was a pretty close call while Mikuru makes tea and Nagato just is silent as always).
Also, most of the CD songs have already been resung by fans for each version (Haruhiko's "My Way", Kyonchan's "Hare Hare Yukai", etc)