Over the w/e I have seen the biggest changes to the Google rankings for my key words that I have seen in 15 months. My ranking has risen a few spaces so I'm not complaining but I don't understand the changes - many of my competitors who clearly don't know about SEO for their sites have risen out of nowhere, whilst spamy "directory" listings have gone. Google are obviously trying to improve quality (and from the end-users point of view have succeeded). Right now I feel worked - all my hard work at SEO - obtaining links from legit sites has come to nothing because my sleepy competitors are being listed anyway.
The Google ranking for my key words look more like a DMOZ listing rather than any algo derived search. In one keyword a very sleepy competitor (in terms of SEO) but a very usefull resouce is suddenly listed 2nd from nowhere- do I detect a human hand in the results?, very strange.