For those of you who have been concerned about any loss of rankings in the latest Google update (nicknamed Update Bourbon), do not panic yet. The update is not yet over. According to Googleguy over on WMW, Here's the advice that I'd give now: take a break from checking ranks for several more days. Bourbon includes something like 3.5 improvements in search quality, and I believe that only a couple are out so far. The 0.5 will go out in a day or so, and the last major change should roll out over the next week or so. Then there will still be some minor changes after that as well. So my "weather report" along the lines of http://www.ysearchblog.com/archives/000095.html would be a recommendation that rankings may still change somewhat over the next several days.
So, kick back, forget about your desperation for up to a week, and hopefully you will return to a pleasant surprise. I wish you all the best.