I think I've arrived at a process that achieves a good balance between alignment and time spent. Here is my first composite using the process, and while the clip hasn't been color timed, it's pretty close. It uses the shadows and highlights from the HDTV broadcast and the mid-tones from the blu-ray. The HDTV clip was put through a good amount of noise reduction, and a nice layer of film grain was added to the final result (can't really make it out in the youtube encode).
Thoughts?