Google had made sitemap submission really easy for webmasters and website owners. Now with Google website submission update, there is no need to specify the type of sitemap you are submitting, Google will automatically determine the type of sitemap you are submitting.
Google recommends it’s webmaster users to use XML sitemaps instead of other sitemap although Google supports RSS 2.0 and Atom 1.0 feeds for web pages, Text files with web page URLs, XML Sitemap files for Video Search, Media-RSS feeds for Video Search, XML Sitemap files for Google Code Search, XML Sitemap files for mobile web pages, XML Sitemap files for geo-data and XML Sitemap files for News.
With Google sitemap submission Webmaster can also submit multiple sitemaps to Google also. For submitting multiple sitemaps to Google, webmasters has to create one index file for all their sitemaps and submit this file to Google sitemap.
How to Create Google Sitemap Index File
I think you are thinking like sukrat, but I think you should cover the other side of the topic in the post too…