Google Sitemaps is a great way to analyze whether Google has indexed all your pages on all of your domains. Furthermore you can monitor the Page Rank on all of your domain and see all the search terms in Google that resulted in traffic to your domain pages. In Sitemaps you can now also see what your position is on the search results for terms you received clicks from.
I will have future articles on Google's latest creation in the very near future as I start to test using sitemaps for several of my domains. Sitemaps has the possibility to be a major development in the way Search Engine Marketing professionals address managing and updating their sites within Google's search engine.