There has been quite a bit of discussion in SEO circles following on the release of Google sitemaps a couple of months ago.
For CMS and blogging platforms there are plugins that aid in the automatic creation of the sitemap and I use it on this site, however it does not cover the areas of the site outside my blog, so the rest of the site is not even mentioned.
Roy Schestowitz has posted an interesting critique of the concept over on his blog and I must admit he does have some very good points (I would have place a comment there, but his captcha code is broken)
Likening Google to Microsoft he does not see any malevolence, but he has highlighted an important trend:
The phenomenon above is the introduction and absorbance of new technologies by force. Google are forcing, not malevolently though, trends of crawling and push for methods to change
If Google do it, then the others may be forced to follow or die.