The DTS "Demostration" disc has a couple segments in 7.1, but my players can't pass the signal for them. There's also a few 7.1 segments on Dolby's "The Sound of High Definition" disc, in both Dolby Digital Plus and TrueHD. My modified A30 can pass the DD+ tracks but not TrueHD. If you play the disc in PCM it only passes in 5.1. There's a few European and Japanese releases that have 7.1 also.
It's the only major US studio movie with 7.1 on HD DVD. However, Vivaldi's Four Seasons and Rachmaninov Piano Concertos No. 2&3 are both 7.1 DTS-HD MA! (no 7.1 Dolby TrueHD or DD+ on anything but the Dolby demo disc)