Google, Yahoo and Ask have come together to embrace a site map standard effective immediately. Microsoft promises to start using the standard later this year. Enhancements to the protocol were announced at Search Engine Strategies New York last week.
Information on the new XML protocol is available at sitemaps.org
Search Engine Watch has a good article covering the announcement.
Since the major engines are going to use this to assist in crawling the web, it makes sense to add this XML site map on your domain to help them index your content. We'll be adding it to all of our clients that contract us for search engine optimization.
