The SEO blogs and forums are awash with people discussing their PageRank changes, their link changes and traffic (or lack of traffic) changes.
Google's being typically Google and not communicating. In fact, I'm yet to see a Google post about the new ability to select the geographic target for your site in natural search. If you didn't notice the change on your own webmaster console then you'd likely find out by ex-Googler Vanessa Fox blogging about it on Search Engine Land.
If I was Yahoo and I wanted to rattle Google's cage then I would tell webmasters of an impending or ongoing re-crawl/index at Yahoo. Further more, I'd invite webmasters for feedback. That's exactly what they've done.
Truth be told - Yahoo probably naturally reached the point where an update was needed at this point and they're probably not doing this just to remind webmasters around the world that Yahoo's far more communicative than Google. Probably.