1script - 5:35 pm on Mar 16, 2010 (gmt 0)
@Pass the Dutchie:
I don't think homepage's cache freshness matters much. I have a site that has been obliterated yesterday but the cache is still only 4-6 hours old - as it has been during recent months. There is still healthy Googlebot activity and the homepage cache updates VERY quickly (2-3 times a day) but Google traffic plummeted to 1/20th of its volume just 48 hours ago.
To add insult to the injury Google has just added sitelinks for that site. I had a tendency to think that sitelinks are a mark of a site that they think is good enough. Guess, not good enough for ranking...