drall - 1:20 am on Jul 20, 2010 (gmt 0)

I believe they do not fall out of the web graph.

We have pages that you can only get to from certain pages that have disappeared from google yet these pages down further still retain pr and rankings without any other external links.

So those pages that have been "ghosted" as we call them around here do still pass some form of juice and are being stored someplace inside G.