After having signed up most of our sites in the Google Sitemap program (and automating the creation and submission of sitemaps using the excellent and free GSiteCrawler which I highly recommend), I began to see signs around the Web that the sitemaps might actually hurt search engine placement — or at least delay it.  I've been searching the past few days, and it seems there is no real consensus as to whether the program helps or hurts. 

Some folks seem to think that their page rank and overall Google placement was hurt by the sitemaps, but from what I can see, all evidence is so far just anecdotal. For now, I think I am going to stop creating sitemaps for new sites — just will allow the search engines to find the sites naturally after placing a few links on our higher ranked sites.