Google has renamed Google Sitemaps to Google Webmaster Tools and has added the service to their Google Webmaster Central channel which includes Site Status Wizard, Submit Content to Google Base & Book Search, Google Webmaster Blog, Google Webmaster Group, and the Google Webmaster Help Center.
Vanessa Fox posts on the Webmaster Central Blog:
We're surrounded by moving boxes and construction dust. To better reflect our goal to provide tools and information to keep you, the webmasters, informed and help you increase your crawl coverage and visibility on Google, we're renaming Google Sitemaps to Google webmaster tools. The Sitemaps protocol remains unchanged and Sitemaps submission mechanisms and reporting is still available from the Sitemaps tab. We're also renaming our blog and Google Group to be more broadly focused on webmaster topics.
You can find handy links to all the tools, the new blog, Google Group, help center and more from our newly launched Google webmaster central. Join us at the blog's new location at googlewebmastercentral.blogspot.com where you'll learn about all the exciting things we're planning. Oh, and please don't forget to update your bookmarks and feed!