Around mid February, we covered a thread discussing the Google Checksum Features. One of those features included an RK or Rank value. It seems as if, the RK values have all been flat-lined. Over at Cre8asite Forums, Jim Westergren updates us that this indeed happened. He also had Matt Cutts from Google say "no comment" on this by stating;
I'm sorry, I can’t shed light on that at this time. :)
Best wishes though, Matt
Forum discussion at Cre8asite Forums.