My self, I had one very important page just disappear. Most of my others have maintained and a few have even swapped which is odd. By swapped I mean having page "ABC.html" in #3 on the SERPs and then that one disappears and is replaced by page "DEF.html". The two pages have similar content but Google swaps out a page that had been ranking for a couple of years with a newer one of similar content value (but fewer inbound links). So far it's always been a new page replacing and old page but all the new pages are also WP blog pages and the old ones are static html. So they aren't equal in that sense.
Several years ago I had my entire static site disappear from Google for six months (it came back stronger than ever all on it's own). But was very tough on my business and it happened during the peak of the recent global economic collapse. After that I vowed to spread my risk by starting a blog. Now my blog brings in most of my traffic and my blog has been immune to every update.
Of course, it makes me nervous relying so much on Google's traffic but that's only because Google controls virtually the entire search market.
In my stats, if I have a 1000 unique visitors from search, maybe 60 would be from Bing, 35 from Yahoo, 20 from others and the rest from Google. I'm not trying to rely on Google so much, it's just that 90% of my audience uses Google.
It's kind of frustrating.