Heh. I wrote this hugely long post, so I pulled a Googler aside and asked “Dan, what do you think of this post?” And after a few helpful comments he said something like, “And, um, you may want to include a paragraph of understandable English at the top.”
Fair enough. Some people don’t want to read the whole mind-numbingly long post while their eyes glaze over. For those people, my short summary would be two-fold. First, I believe the crawl/index team certainly has enough machines to do its job, and we definitely aren’t dropping documents because we’re “out of space.” The second point is that we continue to listen to webmaster feedback to improve our search. We’ve addressed the issues that we’ve seen, but we continue to read through the feedback to look for other ways that we could improve.
People have been asking for more details on “pages dropping from the index” so I thought I’d write down a brain dump of everything I knew about, to have it all in one place. Bear in mind that this is my best recollection, so I’m not claiming that it’s perfect.
(Posted by http://www.mattcutts.com/blog/type/googleseo/)