LAST EDITED ON Oct-19-10 AT 10:02 PM (PST)
If you're an old-time Bomber, the concept of Hilltop shouldn't be anything new. I've maintained that Hilltop is as important to linking as PageRank is.Here's a new patent Google applied for:
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=1&p=1&f=G&l=50&d=PTXT&S1=7,783,639.PN.&OS=pn/7,783,639&RS=PN/7,783,639
Determining quality of linked documents
Abstract
A ranking component ranks documents, such as web pages or web sites, to obtain a ranking score that defines a quality judgment of the document. The ranking score of a particular document is based on the ranking score of the documents which link to it and based on affiliation among the documents.
The important word in the patent's abstract is "affiliation". Affiliation is a word used over and over in the Hilltop documents and is the core principle of Hilltop and in this case it means the relationship between two documents (pages) where there is a link.
And, I don't think it's a coincidence that the word "affiliation" comes up in the new patent as well as in Hilltop. The word and it's use is Google's own fingerprint and probably shows an affiliation between the patent and Hilltop. I believe this is called "irony". 
Basically, Hilltop's primary function is to try to detect whether pages are related in any way, and to score the power of the links accordingly.
This goes way beyond C-block IP addresses and into anything Google can use to try to detect if pages that share a link (or two) are related.
I believe that the effectiveness of link wheels may be directly tied to the concept of Hilltop and affiliated documents. For example, if you spin the same article into 100 different versions, then use them in link structures that link directly to each, Google may be able to detect that the articles are basically the same and just substitute synonyms in certain places...Or they may share affiliate IDs, etc.
The point is, strongly consider Hilltop and ANY AND ALL ways Google may detect your pages/articles/hubs/lenses are "affiliated" to improve your long-term linking benefits.