Neil,
I just want to reiterate that when you say that HDMI 1.4a does not have a standard for 1080p60 for each eye, it's not entirely correct.
HDMI 3D spec does allow formats with full-resolution 1080p @60Hz for each eye, though none of them are mandatory.
The 3D section of HDMI 1.4a defines stereo format identifiers such as frame packing (essentially frame sequential), side-by-side half, side-by-side full, top-bottom half, line interleaved, etc., and these indentifiers can
"extend" every single video mode possible in CEA-861-E - this includes 1080p50/60, as well as all SD, ED, and HD video modes (even 720p100/120 and 1080p100/120 and those stupid "quadruple" SD modes intended for HD audio).
The maximum possible bandwidth in HDMI 1.3 and 1.4 does allow 1080p60 stereo as well, at least in theory; however on the practical side, no HDMI transmitter/receiver has ever been released alllowing the maximum 340 MHz pixel clock, even the latest HDMI 1.4 chips.
So here we go - HDMI has the necessary video modes, but they are optional and no actual products attempt to implement them, because product planners didn't really know or care enough for PC gaming.
See
3D Portion Of HDMI Version 1.4 Available For Download (
1.4a update)
Common stereoscopic video resolutions and bandwidth