Question: is there any evidence that search engines actually use/respect semantic tags like , , , etc.? Or anyone here who knows firsthand from Google? Just because, if I were writing a search engine, I would already have a bunch of "AI"/heuristics logic to tease these things out, since most sites don't use semantic HTML5 -- and it would probably do a solid job, since it's easy to compare a bunch of pages from a sing…
From what I understand, the short answer is "No, they don't". The long answer is "They don't yet, but if we keep telling people they do and everyone starts using semantic HTML, they will".
Eh, I doubt it. The problem with the "semantic web" is that your semantics might not match my semantics. You might use only for the main content of an article-like page, whereas I might use it for each separate piece of text.