I think this a fairly important inflection point. It's when semantic technologies begin creeping in to the mainstream as semantic technologies rather than obscure under the covers functionality as with firefox.
I think the problem is that the semantic web is fundamentally very similar to the sort of 'logical ai' (Prolog, Cyc, etc) that is often blamed for the AI winter.
It's also much more comprehensible than previous attempts. For your average web developer it's just adding a few attributes here and there as tidbits, and as a benefit, you get bells and whistles from google. The big turning point will be if a browser maker with market share builds support for recognizing them - the minute that happens they will pop up on web pages everywhere.
