No. You don’t need to go to 720p at all. You shot 1080i60 footage. Therefore, your project/timeline should be 1080i60. When you’re done editing, export your Master at 1080i60. Bring your Master into encoding software and convert to MPEG-2 @ 480i60 Anamorphic with Upper field dominance. Also encode a .AC3 file for the audio stream. Finally, bring the resulting MPEG-2 and .AC3 files into your DVD Authoring program.
