The one flaw with the original PS3 is that its particular HDMI chipset *cannot* passthrough the HD codecs (Dolby TrueHD & DTS-HD MA) to an HDMI 1.3 receiver for external decoding. So unless they implement a software DTS MA decoder for LPCM output, all you'll ever be able to get is the "core" track.

The newer redesigned 40gb PS3 might use a newer HDMI chipset, which *could* enable passthrough, but I don't think anyone's checked yet (and the software doesn't currently support it regardless).