On November 15, 2006 Google, Microsoft & Yahoo! Back SiteMaps Protocol and Microsoft posted about it back then that they are supporting it.
We are 100% behind this protocol - this kind of collaboration will help improve the search experience for all of our customers, and we are working hard to release full support in 2007. We are starting to alpha test with internal partners such as MSDN and Microsoft Support now. Like all teams at Microsoft, we like to dogfood our work internally to ensure that it is working properly before it is publicly released. Watch this space for an update as soon as we’re done.
So we have been watching this space since November 15 and now more than four months later Microsoft still does not offer a sitemaps submission methodology. Google does, Yahoo! does, they have since about a week after the announcement. Microsoft, we are still waiting. Do you have plans to open up a sitemaps submission page? Even if you set up a page that didn't really work, but made us think it worked, that would be cool. ;-)
Forum discussion at DigitalPoint Forums.