Based on a patent application, SEOmoz has discerned 65 aspects of the Google ranking algorithm.* I counted only 24 that really had much at all to do with enterprise search. This leaves 41 or so focused on spam/SEO-fighting and/or on-page linking issues that have no enterprise parallel. And for more depth, here’s a long article from another SEO site, on a specific phrase-concurrence spam-fighting technique that has no apparent applicability to trusted corpuses.
*I highly recommend this link. It is by far the best single-page overview of web search algorithmic issues I’ve ever seen.
I’ve said it before, but it bears repeating — web search and enterprise search (or search of a constrained corpus) are very different technical problems.