Jim Westergren sent me an email about his new article on Google's RK datapiece. Apparently, it was first reported at WMW, but Jim's done a reasonably good job of pulling out the important pieces and conducting a bit of research.

RK is basically an XML tag that appears in Google's feed of search results, for example:

<T>SEOmoz | Beginner&#39;s Guide to SEO</T>
<RK>6</RK>

There's also a good forum discussion at Cre8asite on the subject, where Jim pointed to a feed from an old datacenter (non-Bigdaddy) for SEOmoz's own RK results, and a BigDaddy datacenter for the same search that revealed entirely different RK numbers. What this piece stands for is still up for questioning, but Jim's research suggests it matches very closely to what our expectations might be of PageRank.

Of course, being someone who hasn't looked at PageRank in a year, I'm not in the best position to make comments about it, other than to say that it's interesting to see that Google is maintaining the antiquated bit of data during this large update. Those who had hinted that BigDaddy spelled the end of PR may have been over-exuberant.