I don’€™t have much to add here, Darren ‘€œProBlogger’€? Rowse has a great post up on what to do if you lose pagerank with Google and the traffic drops. This is indeed (almost) life and death of many bloggers, and the issue is something to have nightmares about if you’€™re relying on search engine traffic. Which you probably are.
Darren feels your pain, if you’€™re in this situation. Go read, and bookmark; it might come in handy in the future’€¦