tedster - 5:40 pm on Jan 21, 2011 (gmt 0) [edited by: tedster at 5:50 pm (utc) on Jan 21, 2011]
The article is worth a read because it gives some idea of Google's algo changes - both current and into the immediate future:
...we recently launched a redesigned document-level classifier that makes it harder for spammy on-page content to rank highly. The new classifier is better at detecting spam on individual web pages, e.g., repeated spammy words—the sort of phrases you tend to see in junky, automated, self-promoting blog comments.
We've also radically improved our ability to detect hacked sites, which were a major source of spam in 2010. And we're evaluating multiple changes that should help drive spam levels even lower, including one change that primarily affects sites that copy others' content and sites with low levels of original content.
[edited by: tedster at 5:50 pm (utc) on Jan 21, 2011]