I can offer the now-patented "gonk comments on the horrors of HDMI" for what that's worth.

Dolby Digital Plus, Dolby TrueHD, and DTS-HD can be supported on three ways: multichannel analog (already possible using the 7.1 analog connections on the 1070, 970, and 990); decoding in the player and multichannel PCM output over HDMI v1.1 (which cannot be added to existing platforms without prohibitively drastic architecture changes); and bitstream output from the player to the receiver over HDMI v1.3 (which also cannot be added to existing platforms without very major changes). As far back as the original launch of the 990 and 1070, Outlaw made their position clear on HDMI: until it became stable, it was unfair to Outlaw's customers to risk saddling them with a version that would prove incompatible with the final iteration. At this point, HDMI v1.3 is a pretty safe bet, but it's also so new is squeaks. As best as we can tell, the successors to the 990, 970, and 1070 will include HDMI v1.3, but there's no official word on when such successors may see the light of day and the best (and somewhat optimistic) guess is probably the early side of 2008.