It sounds as if there will be a few new formats available on high definition discs in the near future. Will the discs also be compatible with current DD and DTS? I would hate to think that my new receiver will be incapable of playing the audio on high definition discs in a few years.

From what I hear, the new DD and DTS formats for high def DVDs will be streamed over PCM and decoded through the DVD player. So, any receiver that has regular DTS or DD should be fine.