And you'll need a disc that will allow the raw bitstream to leave the player, and Blu-ray discs mastered as profile v1.1, and HD DVD discs mastered as advanced content will not allow the raw bitstream to be transmitted out of the player.
But to answer your question westcott; any receiver with six channel analogue inputs or HDMI, will fully support the new audio codex. The audio is decoded and mixed in the player and output as uncompressed multichannel PCM, via HDMI or the six channel out.
As for downconverting to DTS or DD, that happens in the player too, but that DTS or DD signal is only sent out through the optical and coax audio outputs.