diberry - 7:51 pm on Dec 19, 2012 (gmt 0)
Heavy keyword use may cross some threshold and incur a penalty, but changing internal links and/or on-page keyword count and density is only really appropriate if the keyword use was inapproriate in the first place.
YES. I have a theory that Google is in a testing phase with the synonyms, so they're actually intentionally ranking pages more for phrases that don't appear on them than phrases that do, in order to test the machine learning. So, if you used to rank for a phrase on your page, "red water sponges" you might now instead rank for "maroon h20 absorption". I'm seeing a lot of this, particularly on my Penguinized site.
And it sucks for us right now, because there's really nothing we can do. But the future might get interesting. If your sites do well, you could rank for a million more variations on your keyphrases than you ever did before.