I couldn't care less about HDMI 1.3 vs 1.2. It's completely unnecessary, given that DD+ and TrueHD can be happily decoded by the player to 8 channel 192KHz/24bit uncompressed PCM, and transmitted with no loss. There's no advantage to having the receiver decode it instead (which is one reason that very few bother). Other HDMI 1.3 features are equally irrelevant, to HD consoles at least.
However, not supporting any more than two PCM channels is a big deal. Not only would it eliminate high-quality surround, it'd eliminate HDMI's cabling advantage by requiring a separate optical link too. I can't see any hardware reason for this, or software either, unless they just haven't gotten around to implementing it yet.
Does it apply to games too? That'd really suck.