tedster - 6:45 pm on Oct 23, 2010 (gmt 0)
Nothing seems very out of line in the link building efforts you described. Have you also been attracting spontaneous backlinks from "new fans" around the web? You can only get just so far on your own steam, in my opinion, and then your backlinks need to see some kind of a ripple effect spreading out.
Google is not only experiencing some indexing troubles right now, they also appear to be in the midst of a major update. That's pretty much a tradition around Halloween time every year. As users enter more into purchasing intention, the SERPs get shifted into their holiday mode - and then shift back in the new year.
This year, with the Caffeine infrastructure in use, the details of this change look a bit different, and I doubt that it's stable yet. So definitely don't overreact, but do study everything you can about your situation. I agree with the sources recommended so far for backlink data.