http://www.w3.org/TR/html5/ 'W3C Working Draft 4 March 2010'
http://www.w3.org/TR/html401/ 'W3C Recommendation 24 December 1999'
So by 'recommendation', am I to assume you're talking about HTML 4.01?
(edit: again with the downvotes, no answer...)
To be more accurate Apple should have said that it is committed in implementing HTML5 standard, not that it has done it, because at the moment HTML5 is not ready.
From Wikipedia: "Ian Hickson, editor of the HTML5 specification, expects the specification to reach the W3C Candidate Recommendation stage during 2012, and W3C Recommendation in the year 2022 or later. However, many parts of the specification are stable and may be implemented in products"
He was saying that it is useful well before it is an official recommendation. He is a member of the WHAT-WG and Apple was one of the founding members so what he's saying is pretty much in lock-step with apple and the webkit team.
From here http://wiki.whatwg.org/wiki/FAQ:
For a spec to become a REC today, it requires two 100% complete and fully interoperable implementations, which is proven by each successfully passing literally thousands of test cases (20,000 tests for the whole spec would probably be a conservative estimate)
The candidate recommendation phase, which WHATWG expects to happen next year is a much more relevant date. That aside I do wonder if this level of effort isn't just wasted pedantry.
But my point was that giving impression that one company already has it all ready is stretching the truth as HTML5 is still a moving target.