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
Find out whether your site is currently being indexed by Google.
Webmaster tools (including Sitemaps)
Statistics, diagnostics and management of Google's crawling and indexing of your website, including Sitemap submission and reporting.
Submit your content to Google
Learn about submitting content for Google properties such as Google Base and Google Book Search.
Webmaster Central Blog
The latest news and info on how Google crawls and indexes websites.
Google's discussion group for webmasters
Talk with your fellow webmasters and share your feedback.
Webmaster help center
See answers to frequently asked questions about crawling, indexing, ranking and other webmaster issues.