In response to JR's questions, I'm finding over the last 6 weeks or so that google is re-acting in some strange ways. Pages that have held good SERPS for months, literally slipped over night.
Although I try not to feed into SE propaganda, especially that associated to google, I have been spending some time over at Matt Cutts blog in the last month.
For those who don't have the URL: xxxhttp://www.mattcutts.com/blog/
Google will always be tweaking its algorithms, in hope of achieving greater (should I say) delivering more valid search results. I did notice through my stats that google may have completed a mini dance 2 - 3 weeks ago, as I had been hit by a number of data center IP's.
Anyway my point is, and going on past events, we may very well see a BIG shift in google results soon.
But it's a bit too early for me to open a book on the odds & to start accepting bets
The only advice I can offer is stick to the rules, white hat everything. If your convinced that you have a workable theory, try it out on a domain name your not using, least if it turns to cr#p, you don't ruin a completely good web site
Cheers
Dave