An hour or so past the above post I;m seeing massive fluctuations in the G SERPS for my major site, like nothing I've ever, ever seen.
Pages are going up and down 40 positions or so for no apparent reason. If your site is down don't do anything for a few days, it may well pop up as number one tomorrow.
Why the fluctuations though? It doesn't make sense from my experience as a computer tester. You do a change to the algo, you wait a couple of days to analyse how it goes and then you tweak it and repeat the process. What is happening with G is testing in a live environment, it's not sensible and one day they will come a cropper.
The fundamental things in life still, most definitely, DO apply.