The HD-DVD players and Blu-ray players decode True HD and DTS-HD internally and can be output over analog 5.1 outputs or HDMI using Linear PCM. The difference should be almost neglegible between 7.1 LPCM and True HD, the only difference would be where it is decoded.
Waiting for 1.3 is kind of silly because not only can we get high resolution audio via 7.1 LPCM, but we also get our 1080p. I don't expect the first lines of 1.3 able receivers to have any better decoding than the HD players they have now.