Ok some more info.....
On the topic of the page I made the changes to which went from 38 to 4, and I then rolled the same change out to about 20 other domains.
I am seeing the first cache updates to one of the changed pages.
The change was made 19/Aug/2010 to the index page of a site.
At the time I made my page changes - the cache date was 02/Aug/2010
Today - 27/Aug -
1. Find my site in the SERP.
2. Click on Cached Link
3. Cache date is 02/Aug/2010 - Old page shows in cache
4. Click Back Button
5. Click on Cached Link again (same link - no refresh)
6. Cache date is 23/Aug/2010 - New page shows in cache with my changes
So - they are showing me two cached versions at the moment.
I can say at this stage - whilst its clear that goofle have seen my changes, I would assume as yet that they are not factored. I will also have to assume for now that they will not be factored in the ranking until the old cache version dissapears - maybe - a couple of assumptions there being made in the HOPE my changes will affect my rank like they did on the initial site from 38 to 4.
I just get the feeling its doing its thing at the moment - well Im hoping so - because at this point in proceedings theres NO ranking change.
You can use these dates as a milestone for your own changes going through.
Hope this helps someone - I could certainly do with some help - I think the men in white coats are coming for me. Looking at cache dates - sheez whats life come to?