I've encountered some people who basically don't believe that Google will blacklist a site for dodgy search engine optimisation activities. Boing Boing has posted an article about BMW Germany's site (bmw.de) site being removed from the index for serving entirely different content out to search engines: Matt Cutts: Gadgets, Google, and SEO | Ramping up on international webspam.

Cutts has also posted on how to get back into the index: Matt Cutts: Gadgets, Google, and SEO | Filing a reinclusion request.

I'm still not convinced that Google's new stance won't end up blacklisting or lowering the pagerank of sites with legitimate alternative content. Time will tell, I guess. Not to mention the fact that pagerank is basically a mystery anyway, so who would know?

Update 2009.04.26: Google has posted a video with tips on filing a good reconsideration request. Official Google Webmaster Central Blog: Tips on requesting reconsideration.