Google Webmaster Central is an awesome product and I personally love it. It offers ways for SEOs and Webmasters to learn more about how Google is treating their site. It also offers ways for Webmasters to notify Google of content by submitting a Google Sitemap to them. But some SEOs suggest that you should not submit a Sitemap to Google.
Rand at SEOmoz suggests that we should verify our sites in Google Webmaster Central but do not submit our content via a Google Sitemaps. Why? Well, if Google is excluding your pages in the normal crawl, then there may be a reason for that – says Rand and other SEOs. So losing that data by submitting a Sitemap may put you somewhat in the dark about your site performance in Google.
Does this mean you should not use Sitemaps? Absolutely not! It totally depends on your specific case. I primarily verify my sites in Google but rarely ever submit a Sitemap – however, I have submitted Sitemaps for specific cases.