This is probably the most amazing thing to happen in SEO for a long time, Google has given one of it’s sites a PageRank penalty for buying links.
Most people probably heard about Google Japan paying bloggers to write posts about them earlier in the week. The posts had disclosure but the links were not nofollow links.
Hobo Web points to a Twitter message from Matt Cutts confirming the penalty:
I doubt Google Japan will lose any search traffic because of this.