I've never read anything I would consider truly definitive about this. However, everything I have read points to late 2013 or maybe even early 2014 (like say simultaneous with CES). That would be a bummer!
Also interesting from Richard's post is that it seems like they're saying that the 70" UHD set will actually be cheaper than the 80" HD set. Didn't they say MSRP on the 80" would be like $5k? Anyone remember?
EDIT: from the hdmi forum FAQ:
"When does the HDMI Forum expect to release the next version of the HDMI Specification?
The HDMI Forum Members and the Board of Directors intend to have the next version of the HDMI Specification available for release sometime in late-2012."
Later in the FAQ it specifically says this newer version is subsequent to v1.4b. Anyway, assuming hardware makers are part of the technical working group, I guess it's possible that they could be shipping v2.0 compliant hardware more or less simultaneous with the release of the spec, though it wouldn't be surprising for there to be at least a short lag.
Anyone know how it went with prior updates? Did hardware ship immediately or some time after the announcement?