Yesterday was out the news that Google will adopt soon the new proposed rel="nofollow" tag for links to combat spamming, expecially on Blogs... after the news rumours, on the official Google's Blog the news was confirmed.
Curious, today also Yahoo and MSN are making the same announcement... an alliance against spamming? 
Maybe this is not the key to destroy the spamming phenomenon, but it's an important step against it.