dazzlindonna - 1:20 pm on Nov 23, 2010 (gmt 0)
Quick note: A week after I changed a page, the SERPs are now showing the new Instant Preview image. Latest cache shows a date 3 days ago. So...4 days to new cache, and another 3 days to new image preview. Obviously, that will be different for different sites/pages, but thought I'd at least share my one test with you all.