Guido - 1:27 pm on May 18, 2008 (gmt 0)

G certainly used the "age" knob in the last days in favor to older sites

I don't think so. My 5yo site is acting like a yoyo. Within hours I'm on top five, in the middle of nowhere or buried on page 20 or so.
Other strange things:
I'm getting visit for the most unusual keywords.
Search for keywordA Google.com returns pageA (which is correct)
Search for KeywordA Google.co.au returns PageB which even if it contains KeywordA it's not specific to that word/sentence.
I also lost ranking on .co.uk and at my previous place there is a post of mine in yahoo-answer with reference to my site. It's rather hysterical.